Physical characteristics of moving obj...

单项选择题The Impossibility of Rapid Energy Transitions A) Politicians are fond of promising rapid energy transitions. Whether it is a transition from imported to domestic oil or from coal-powered electricity production to natural-gas power plants, politicians love to talk big. Unfortunately for them (and often the taxpayers), our energy systems are a bit like an aircraft carrier: they are unbelievably expensive, they are built to last for a very long time, they have a huge amount of inertia (meaning it takes a lot of energy to set them moving), and they have a lot of momentum once they are set in motion. No matter how hard you try, you can’t turn something that large on a dime (10美分硬币), or even a few thousand dimes. B) In physics, moving objects have two characteristics relevant to understanding the dynamics of energy systems: inertia and momentum. Inertia is the resistance of objects to efforts to change their state of motion. If you try to push a boulder (大圆石), it pushes you back. Once you have started the boulder rolling, it develops momentum, which is defined by its mass and velocity. Momentum is said to be "conserved," that is, once you build it up, it has to go somewhere. So a heavy object, like a football player moving at a high speed, has a lot of momentum-that is, once he is moving, it is hard to change his state of motion. If you want to change his course, you have only a few choices: you can stop him, transferring (possibly painfully) some of his kinetic energy (动能) to your own body, or you can approach alongside and slowly apply pressure to gradually alter his course. C) But there are other kinds of momentum as well. After all, we don’t speak only of objects or people as having momentum; we speak of entire systems having momentum. Whether it’s a sports team or a presidential campaign, everybody relishes having the big momentum, because it makes them harder to stop or change direction. D) One kind of momentum is technological momentum. When a technology is deployed, its impacts reach far beyond itself. Consider the incandescent (白炽灯的) bulb, an object currently hated by many environmentalists and energy-efficiency advocates. The incandescent light bulb, invented by Thomas Edison, which came to be the symbol of inspiration, has been developed into hundreds, if not thousands, of forms. Today, a visit to a lighting store reveals a stunning array of choices. There are standard-shaped bulbs, flame-shaped bulbs, colored globe-shaped bulbs, and more. It is quite easy, with all that choice, to change a light bulb. E) But the momentum of incandescent lighting does not stop there. All of those specialized bulbs led to the building of specialized light fixtures, from the desk lamp you study by, to the ugly but beloved hand-painted Chinese lamp you inherited from your grandmother, to the ceiling fixture in your closet, to the light in your oven or refrigerator, and to the light that the dentist points at you. It is easy to change a light bulb, sure, but it is harder to change the bulb and its fixture. F) And there is more to the story, because not only are the devices that house incandescent bulbs shaped to their underlying characteristics, but rooms and entire buildings have been designed in accordance with how incandescent lighting reflects off walls and windows. G) As lighting expert Howard Brandston points out, "Generally, there are no bad light sources, only bad applications." There are some very commendable characteristics of the CFL [compact fluorescent(荧光的) light bulb], yet the selection of any light source remains inseparable from the luminaire (照明装置) that houses it, along with the space in which both are installed, and lighting requirements that need to be satisfied. The lamp, the fixture, and the room, all three must work in concert for the true benefits of end-users. If the CFL should be used for lighting a particular space, or an object within that space, the fixture must be designed to work with that lamp, and that fixture with the room. It is a symbiotic (共生的) relationship. A CFL cannot be simply installed in an incandescent fixture and then expected to produce a visual appearance that is more than washed out, foggy, and dim. The whole fixture must be replaced-light source and luminaire-and this is never an inexpensive proposition. H) And Brandston knows a thing or two about lighting, being the man who illuminated the Statue of Liberty. I) Another type of momentum we have to think about when planning for changes in our energy systems is labor-pool momentum. It is one thing to say that we are going to shift 30 percent of our electricity supply from, say, coal to nuclear power in 20 years. But it is another thing to have a supply of trained talent that could let you carry out this promise. That is because the engineers, designers, regulators, operators, and all of the other skilled people needed for the new energy industry are specialists who have to be trained first (or retrained, if they are the ones being laid off in some related industry), and education, like any other complicated endeavor, takes time. And not only do our prospective new energy workers have to be trained, they have to be trained in the right sequence. One needs the designers, and perhaps the regulators, before the builders and operators, and each group of workers in training has to know there is work waiting beyond graduation. In some cases, colleges and universities might have to change their training programs, adding another layer of difficulty. J) By far the biggest type of momentum that comes into play when it comes to changing our energy systems is economic momentum. The major components of our energy systems, such as fuel production, refining, electrical generation and distribution, are costly installations that have lengthy life spans. They have to operate for long periods of time before the costs of development have been recovered. When investors put up money to build, say, a nuclear power plant, they expect to earn that money back over the planned life of the plant, which is typically between 40 and 60 years. Some coal power plants in the United States have operated for more than 70 years! The oldest continuously operated commercial hydro-electric plant in the United States is on New York’s Hudson River, and it went into commercial service in 1898. K) As Vaclav Smil points out, "All the forecasts, plans, and anticipations cited above have failed so miserably because their authors and promoters thought the transitions they hoped to implement would proceed unlike all previous energy transitions, and that their progress could be accelerated in an unprecedented manner." L) When you hear people speaking of making a rapid transition toward any type of energy, whether it is a switch from coal to nuclear power, or a switch from gasoline-powered cars to electric cars, or even a switch from an incandescent to a fluorescent light, understanding energy system inertia and momentum can help you decide whether their plans are feasible. Physical characteristics of moving objects help explain the dynamics of energy systems.

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1.单项选择题The Impossibility of Rapid Energy Transitions A) Politicians are fond of promising rapid energy transitions. Whether it is a transition from imported to domestic oil or from coal-powered electricity production to natural-gas power plants, politicians love to talk big. Unfortunately for them (and often the taxpayers), our energy systems are a bit like an aircraft carrier: they are unbelievably expensive, they are built to last for a very long time, they have a huge amount of inertia (meaning it takes a lot of energy to set them moving), and they have a lot of momentum once they are set in motion. No matter how hard you try, you can’t turn something that large on a dime (10美分硬币), or even a few thousand dimes. B) In physics, moving objects have two characteristics relevant to understanding the dynamics of energy systems: inertia and momentum. Inertia is the resistance of objects to efforts to change their state of motion. If you try to push a boulder (大圆石), it pushes you back. Once you have started the boulder rolling, it develops momentum, which is defined by its mass and velocity. Momentum is said to be "conserved," that is, once you build it up, it has to go somewhere. So a heavy object, like a football player moving at a high speed, has a lot of momentum-that is, once he is moving, it is hard to change his state of motion. If you want to change his course, you have only a few choices: you can stop him, transferring (possibly painfully) some of his kinetic energy (动能) to your own body, or you can approach alongside and slowly apply pressure to gradually alter his course. C) But there are other kinds of momentum as well. After all, we don’t speak only of objects or people as having momentum; we speak of entire systems having momentum. Whether it’s a sports team or a presidential campaign, everybody relishes having the big momentum, because it makes them harder to stop or change direction. D) One kind of momentum is technological momentum. When a technology is deployed, its impacts reach far beyond itself. Consider the incandescent (白炽灯的) bulb, an object currently hated by many environmentalists and energy-efficiency advocates. The incandescent light bulb, invented by Thomas Edison, which came to be the symbol of inspiration, has been developed into hundreds, if not thousands, of forms. Today, a visit to a lighting store reveals a stunning array of choices. There are standard-shaped bulbs, flame-shaped bulbs, colored globe-shaped bulbs, and more. It is quite easy, with all that choice, to change a light bulb. E) But the momentum of incandescent lighting does not stop there. All of those specialized bulbs led to the building of specialized light fixtures, from the desk lamp you study by, to the ugly but beloved hand-painted Chinese lamp you inherited from your grandmother, to the ceiling fixture in your closet, to the light in your oven or refrigerator, and to the light that the dentist points at you. It is easy to change a light bulb, sure, but it is harder to change the bulb and its fixture. F) And there is more to the story, because not only are the devices that house incandescent bulbs shaped to their underlying characteristics, but rooms and entire buildings have been designed in accordance with how incandescent lighting reflects off walls and windows. G) As lighting expert Howard Brandston points out, "Generally, there are no bad light sources, only bad applications." There are some very commendable characteristics of the CFL [compact fluorescent(荧光的) light bulb], yet the selection of any light source remains inseparable from the luminaire (照明装置) that houses it, along with the space in which both are installed, and lighting requirements that need to be satisfied. The lamp, the fixture, and the room, all three must work in concert for the true benefits of end-users. If the CFL should be used for lighting a particular space, or an object within that space, the fixture must be designed to work with that lamp, and that fixture with the room. It is a symbiotic (共生的) relationship. A CFL cannot be simply installed in an incandescent fixture and then expected to produce a visual appearance that is more than washed out, foggy, and dim. The whole fixture must be replaced-light source and luminaire-and this is never an inexpensive proposition. H) And Brandston knows a thing or two about lighting, being the man who illuminated the Statue of Liberty. I) Another type of momentum we have to think about when planning for changes in our energy systems is labor-pool momentum. It is one thing to say that we are going to shift 30 percent of our electricity supply from, say, coal to nuclear power in 20 years. But it is another thing to have a supply of trained talent that could let you carry out this promise. That is because the engineers, designers, regulators, operators, and all of the other skilled people needed for the new energy industry are specialists who have to be trained first (or retrained, if they are the ones being laid off in some related industry), and education, like any other complicated endeavor, takes time. And not only do our prospective new energy workers have to be trained, they have to be trained in the right sequence. One needs the designers, and perhaps the regulators, before the builders and operators, and each group of workers in training has to know there is work waiting beyond graduation. In some cases, colleges and universities might have to change their training programs, adding another layer of difficulty. J) By far the biggest type of momentum that comes into play when it comes to changing our energy systems is economic momentum. The major components of our energy systems, such as fuel production, refining, electrical generation and distribution, are costly installations that have lengthy life spans. They have to operate for long periods of time before the costs of development have been recovered. When investors put up money to build, say, a nuclear power plant, they expect to earn that money back over the planned life of the plant, which is typically between 40 and 60 years. Some coal power plants in the United States have operated for more than 70 years! The oldest continuously operated commercial hydro-electric plant in the United States is on New York’s Hudson River, and it went into commercial service in 1898. K) As Vaclav Smil points out, "All the forecasts, plans, and anticipations cited above have failed so miserably because their authors and promoters thought the transitions they hoped to implement would proceed unlike all previous energy transitions, and that their progress could be accelerated in an unprecedented manner." L) When you hear people speaking of making a rapid transition toward any type of energy, whether it is a switch from coal to nuclear power, or a switch from gasoline-powered cars to electric cars, or even a switch from an incandescent to a fluorescent light, understanding energy system inertia and momentum can help you decide whether their plans are feasible. The application of a technology can impact areas beyond itself.

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2.单项选择题The Impossibility of Rapid Energy Transitions A) Politicians are fond of promising rapid energy transitions. Whether it is a transition from imported to domestic oil or from coal-powered electricity production to natural-gas power plants, politicians love to talk big. Unfortunately for them (and often the taxpayers), our energy systems are a bit like an aircraft carrier: they are unbelievably expensive, they are built to last for a very long time, they have a huge amount of inertia (meaning it takes a lot of energy to set them moving), and they have a lot of momentum once they are set in motion. No matter how hard you try, you can’t turn something that large on a dime (10美分硬币), or even a few thousand dimes. B) In physics, moving objects have two characteristics relevant to understanding the dynamics of energy systems: inertia and momentum. Inertia is the resistance of objects to efforts to change their state of motion. If you try to push a boulder (大圆石), it pushes you back. Once you have started the boulder rolling, it develops momentum, which is defined by its mass and velocity. Momentum is said to be "conserved," that is, once you build it up, it has to go somewhere. So a heavy object, like a football player moving at a high speed, has a lot of momentum-that is, once he is moving, it is hard to change his state of motion. If you want to change his course, you have only a few choices: you can stop him, transferring (possibly painfully) some of his kinetic energy (动能) to your own body, or you can approach alongside and slowly apply pressure to gradually alter his course. C) But there are other kinds of momentum as well. After all, we don’t speak only of objects or people as having momentum; we speak of entire systems having momentum. Whether it’s a sports team or a presidential campaign, everybody relishes having the big momentum, because it makes them harder to stop or change direction. D) One kind of momentum is technological momentum. When a technology is deployed, its impacts reach far beyond itself. Consider the incandescent (白炽灯的) bulb, an object currently hated by many environmentalists and energy-efficiency advocates. The incandescent light bulb, invented by Thomas Edison, which came to be the symbol of inspiration, has been developed into hundreds, if not thousands, of forms. Today, a visit to a lighting store reveals a stunning array of choices. There are standard-shaped bulbs, flame-shaped bulbs, colored globe-shaped bulbs, and more. It is quite easy, with all that choice, to change a light bulb. E) But the momentum of incandescent lighting does not stop there. All of those specialized bulbs led to the building of specialized light fixtures, from the desk lamp you study by, to the ugly but beloved hand-painted Chinese lamp you inherited from your grandmother, to the ceiling fixture in your closet, to the light in your oven or refrigerator, and to the light that the dentist points at you. It is easy to change a light bulb, sure, but it is harder to change the bulb and its fixture. F) And there is more to the story, because not only are the devices that house incandescent bulbs shaped to their underlying characteristics, but rooms and entire buildings have been designed in accordance with how incandescent lighting reflects off walls and windows. G) As lighting expert Howard Brandston points out, "Generally, there are no bad light sources, only bad applications." There are some very commendable characteristics of the CFL [compact fluorescent(荧光的) light bulb], yet the selection of any light source remains inseparable from the luminaire (照明装置) that houses it, along with the space in which both are installed, and lighting requirements that need to be satisfied. The lamp, the fixture, and the room, all three must work in concert for the true benefits of end-users. If the CFL should be used for lighting a particular space, or an object within that space, the fixture must be designed to work with that lamp, and that fixture with the room. It is a symbiotic (共生的) relationship. A CFL cannot be simply installed in an incandescent fixture and then expected to produce a visual appearance that is more than washed out, foggy, and dim. The whole fixture must be replaced-light source and luminaire-and this is never an inexpensive proposition. H) And Brandston knows a thing or two about lighting, being the man who illuminated the Statue of Liberty. I) Another type of momentum we have to think about when planning for changes in our energy systems is labor-pool momentum. It is one thing to say that we are going to shift 30 percent of our electricity supply from, say, coal to nuclear power in 20 years. But it is another thing to have a supply of trained talent that could let you carry out this promise. That is because the engineers, designers, regulators, operators, and all of the other skilled people needed for the new energy industry are specialists who have to be trained first (or retrained, if they are the ones being laid off in some related industry), and education, like any other complicated endeavor, takes time. And not only do our prospective new energy workers have to be trained, they have to be trained in the right sequence. One needs the designers, and perhaps the regulators, before the builders and operators, and each group of workers in training has to know there is work waiting beyond graduation. In some cases, colleges and universities might have to change their training programs, adding another layer of difficulty. J) By far the biggest type of momentum that comes into play when it comes to changing our energy systems is economic momentum. The major components of our energy systems, such as fuel production, refining, electrical generation and distribution, are costly installations that have lengthy life spans. They have to operate for long periods of time before the costs of development have been recovered. When investors put up money to build, say, a nuclear power plant, they expect to earn that money back over the planned life of the plant, which is typically between 40 and 60 years. Some coal power plants in the United States have operated for more than 70 years! The oldest continuously operated commercial hydro-electric plant in the United States is on New York’s Hudson River, and it went into commercial service in 1898. K) As Vaclav Smil points out, "All the forecasts, plans, and anticipations cited above have failed so miserably because their authors and promoters thought the transitions they hoped to implement would proceed unlike all previous energy transitions, and that their progress could be accelerated in an unprecedented manner." L) When you hear people speaking of making a rapid transition toward any type of energy, whether it is a switch from coal to nuclear power, or a switch from gasoline-powered cars to electric cars, or even a switch from an incandescent to a fluorescent light, understanding energy system inertia and momentum can help you decide whether their plans are feasible. The biggest obstacle to energy transition is that the present energy system is too expensive to replace.

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3.单项选择题The Impossibility of Rapid Energy Transitions A) Politicians are fond of promising rapid energy transitions. Whether it is a transition from imported to domestic oil or from coal-powered electricity production to natural-gas power plants, politicians love to talk big. Unfortunately for them (and often the taxpayers), our energy systems are a bit like an aircraft carrier: they are unbelievably expensive, they are built to last for a very long time, they have a huge amount of inertia (meaning it takes a lot of energy to set them moving), and they have a lot of momentum once they are set in motion. No matter how hard you try, you can’t turn something that large on a dime (10美分硬币), or even a few thousand dimes. B) In physics, moving objects have two characteristics relevant to understanding the dynamics of energy systems: inertia and momentum. Inertia is the resistance of objects to efforts to change their state of motion. If you try to push a boulder (大圆石), it pushes you back. Once you have started the boulder rolling, it develops momentum, which is defined by its mass and velocity. Momentum is said to be "conserved," that is, once you build it up, it has to go somewhere. So a heavy object, like a football player moving at a high speed, has a lot of momentum-that is, once he is moving, it is hard to change his state of motion. If you want to change his course, you have only a few choices: you can stop him, transferring (possibly painfully) some of his kinetic energy (动能) to your own body, or you can approach alongside and slowly apply pressure to gradually alter his course. C) But there are other kinds of momentum as well. After all, we don’t speak only of objects or people as having momentum; we speak of entire systems having momentum. Whether it’s a sports team or a presidential campaign, everybody relishes having the big momentum, because it makes them harder to stop or change direction. D) One kind of momentum is technological momentum. When a technology is deployed, its impacts reach far beyond itself. Consider the incandescent (白炽灯的) bulb, an object currently hated by many environmentalists and energy-efficiency advocates. The incandescent light bulb, invented by Thomas Edison, which came to be the symbol of inspiration, has been developed into hundreds, if not thousands, of forms. Today, a visit to a lighting store reveals a stunning array of choices. There are standard-shaped bulbs, flame-shaped bulbs, colored globe-shaped bulbs, and more. It is quite easy, with all that choice, to change a light bulb. E) But the momentum of incandescent lighting does not stop there. All of those specialized bulbs led to the building of specialized light fixtures, from the desk lamp you study by, to the ugly but beloved hand-painted Chinese lamp you inherited from your grandmother, to the ceiling fixture in your closet, to the light in your oven or refrigerator, and to the light that the dentist points at you. It is easy to change a light bulb, sure, but it is harder to change the bulb and its fixture. F) And there is more to the story, because not only are the devices that house incandescent bulbs shaped to their underlying characteristics, but rooms and entire buildings have been designed in accordance with how incandescent lighting reflects off walls and windows. G) As lighting expert Howard Brandston points out, "Generally, there are no bad light sources, only bad applications." There are some very commendable characteristics of the CFL [compact fluorescent(荧光的) light bulb], yet the selection of any light source remains inseparable from the luminaire (照明装置) that houses it, along with the space in which both are installed, and lighting requirements that need to be satisfied. The lamp, the fixture, and the room, all three must work in concert for the true benefits of end-users. If the CFL should be used for lighting a particular space, or an object within that space, the fixture must be designed to work with that lamp, and that fixture with the room. It is a symbiotic (共生的) relationship. A CFL cannot be simply installed in an incandescent fixture and then expected to produce a visual appearance that is more than washed out, foggy, and dim. The whole fixture must be replaced-light source and luminaire-and this is never an inexpensive proposition. H) And Brandston knows a thing or two about lighting, being the man who illuminated the Statue of Liberty. I) Another type of momentum we have to think about when planning for changes in our energy systems is labor-pool momentum. It is one thing to say that we are going to shift 30 percent of our electricity supply from, say, coal to nuclear power in 20 years. But it is another thing to have a supply of trained talent that could let you carry out this promise. That is because the engineers, designers, regulators, operators, and all of the other skilled people needed for the new energy industry are specialists who have to be trained first (or retrained, if they are the ones being laid off in some related industry), and education, like any other complicated endeavor, takes time. And not only do our prospective new energy workers have to be trained, they have to be trained in the right sequence. One needs the designers, and perhaps the regulators, before the builders and operators, and each group of workers in training has to know there is work waiting beyond graduation. In some cases, colleges and universities might have to change their training programs, adding another layer of difficulty. J) By far the biggest type of momentum that comes into play when it comes to changing our energy systems is economic momentum. The major components of our energy systems, such as fuel production, refining, electrical generation and distribution, are costly installations that have lengthy life spans. They have to operate for long periods of time before the costs of development have been recovered. When investors put up money to build, say, a nuclear power plant, they expect to earn that money back over the planned life of the plant, which is typically between 40 and 60 years. Some coal power plants in the United States have operated for more than 70 years! The oldest continuously operated commercial hydro-electric plant in the United States is on New York’s Hudson River, and it went into commercial service in 1898. K) As Vaclav Smil points out, "All the forecasts, plans, and anticipations cited above have failed so miserably because their authors and promoters thought the transitions they hoped to implement would proceed unlike all previous energy transitions, and that their progress could be accelerated in an unprecedented manner." L) When you hear people speaking of making a rapid transition toward any type of energy, whether it is a switch from coal to nuclear power, or a switch from gasoline-powered cars to electric cars, or even a switch from an incandescent to a fluorescent light, understanding energy system inertia and momentum can help you decide whether their plans are feasible. The problem with lighting, if it arises, often doesn’t lie in light sources but in their applications.

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4.单项选择题The Impossibility of Rapid Energy Transitions A) Politicians are fond of promising rapid energy transitions. Whether it is a transition from imported to domestic oil or from coal-powered electricity production to natural-gas power plants, politicians love to talk big. Unfortunately for them (and often the taxpayers), our energy systems are a bit like an aircraft carrier: they are unbelievably expensive, they are built to last for a very long time, they have a huge amount of inertia (meaning it takes a lot of energy to set them moving), and they have a lot of momentum once they are set in motion. No matter how hard you try, you can’t turn something that large on a dime (10美分硬币), or even a few thousand dimes. B) In physics, moving objects have two characteristics relevant to understanding the dynamics of energy systems: inertia and momentum. Inertia is the resistance of objects to efforts to change their state of motion. If you try to push a boulder (大圆石), it pushes you back. Once you have started the boulder rolling, it develops momentum, which is defined by its mass and velocity. Momentum is said to be "conserved," that is, once you build it up, it has to go somewhere. So a heavy object, like a football player moving at a high speed, has a lot of momentum-that is, once he is moving, it is hard to change his state of motion. If you want to change his course, you have only a few choices: you can stop him, transferring (possibly painfully) some of his kinetic energy (动能) to your own body, or you can approach alongside and slowly apply pressure to gradually alter his course. C) But there are other kinds of momentum as well. After all, we don’t speak only of objects or people as having momentum; we speak of entire systems having momentum. Whether it’s a sports team or a presidential campaign, everybody relishes having the big momentum, because it makes them harder to stop or change direction. D) One kind of momentum is technological momentum. When a technology is deployed, its impacts reach far beyond itself. Consider the incandescent (白炽灯的) bulb, an object currently hated by many environmentalists and energy-efficiency advocates. The incandescent light bulb, invented by Thomas Edison, which came to be the symbol of inspiration, has been developed into hundreds, if not thousands, of forms. Today, a visit to a lighting store reveals a stunning array of choices. There are standard-shaped bulbs, flame-shaped bulbs, colored globe-shaped bulbs, and more. It is quite easy, with all that choice, to change a light bulb. E) But the momentum of incandescent lighting does not stop there. All of those specialized bulbs led to the building of specialized light fixtures, from the desk lamp you study by, to the ugly but beloved hand-painted Chinese lamp you inherited from your grandmother, to the ceiling fixture in your closet, to the light in your oven or refrigerator, and to the light that the dentist points at you. It is easy to change a light bulb, sure, but it is harder to change the bulb and its fixture. F) And there is more to the story, because not only are the devices that house incandescent bulbs shaped to their underlying characteristics, but rooms and entire buildings have been designed in accordance with how incandescent lighting reflects off walls and windows. G) As lighting expert Howard Brandston points out, "Generally, there are no bad light sources, only bad applications." There are some very commendable characteristics of the CFL [compact fluorescent(荧光的) light bulb], yet the selection of any light source remains inseparable from the luminaire (照明装置) that houses it, along with the space in which both are installed, and lighting requirements that need to be satisfied. The lamp, the fixture, and the room, all three must work in concert for the true benefits of end-users. If the CFL should be used for lighting a particular space, or an object within that space, the fixture must be designed to work with that lamp, and that fixture with the room. It is a symbiotic (共生的) relationship. A CFL cannot be simply installed in an incandescent fixture and then expected to produce a visual appearance that is more than washed out, foggy, and dim. The whole fixture must be replaced-light source and luminaire-and this is never an inexpensive proposition. H) And Brandston knows a thing or two about lighting, being the man who illuminated the Statue of Liberty. I) Another type of momentum we have to think about when planning for changes in our energy systems is labor-pool momentum. It is one thing to say that we are going to shift 30 percent of our electricity supply from, say, coal to nuclear power in 20 years. But it is another thing to have a supply of trained talent that could let you carry out this promise. That is because the engineers, designers, regulators, operators, and all of the other skilled people needed for the new energy industry are specialists who have to be trained first (or retrained, if they are the ones being laid off in some related industry), and education, like any other complicated endeavor, takes time. And not only do our prospective new energy workers have to be trained, they have to be trained in the right sequence. One needs the designers, and perhaps the regulators, before the builders and operators, and each group of workers in training has to know there is work waiting beyond graduation. In some cases, colleges and universities might have to change their training programs, adding another layer of difficulty. J) By far the biggest type of momentum that comes into play when it comes to changing our energy systems is economic momentum. The major components of our energy systems, such as fuel production, refining, electrical generation and distribution, are costly installations that have lengthy life spans. They have to operate for long periods of time before the costs of development have been recovered. When investors put up money to build, say, a nuclear power plant, they expect to earn that money back over the planned life of the plant, which is typically between 40 and 60 years. Some coal power plants in the United States have operated for more than 70 years! The oldest continuously operated commercial hydro-electric plant in the United States is on New York’s Hudson River, and it went into commercial service in 1898. K) As Vaclav Smil points out, "All the forecasts, plans, and anticipations cited above have failed so miserably because their authors and promoters thought the transitions they hoped to implement would proceed unlike all previous energy transitions, and that their progress could be accelerated in an unprecedented manner." L) When you hear people speaking of making a rapid transition toward any type of energy, whether it is a switch from coal to nuclear power, or a switch from gasoline-powered cars to electric cars, or even a switch from an incandescent to a fluorescent light, understanding energy system inertia and momentum can help you decide whether their plans are feasible. Energy systems, like an aircraft carrier set in motion, have huge momentum.

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5.单项选择题Passage Two Questions 61 to 65 are based on the following passage. Across the board, American colleges and universities are not doing a very good job of preparing their students for the workplace or their post-graduation lives. This was made clear by the work of two sociologists, Richard Arum and Josipa Roksa. In 2011 they released a landmark study titled "Academically Adrift," which documented the lack of intellectual growth experienced by many people enrolled in college. In particular, Arum and Roksa found, college students were not developing the critical thinking, analytic reasoning and other higher-level skills that are necessary to thrive in today’s knowledge-based economy and to lead our nation in a time of complex challenges and dynamic change. Arum and Roksa placed the blame for students’ lack of learning on a watered-down college curriculum and lowered undergraduate work standards. Although going to college is supposed to be a full-time job, students spent, on average, only 12 to 14 hours a week studying and many were skating through their semesters without doing a significant amount of reading and writing. Students who take more challenging classes and spend more time studying do learn more. But the priorities of many undergraduates are with extracurricular activities, playing sports, and partying and socializing. Laura Hamilton, the author of a study on parents who pay for college, will argue in a forthcoming book that college administrations are overly concerned with the social and athletic activities of their students. In Paying for the Party, Hamilton describes what she calls the "party pathway," which eases many students through college, helped along by various clubs that send students into the party scene and a host of easier majors. By sanctioning this watered-down version of college, universities are "catering to the social and educational needs of wealthy students at the expense of others" who won’t enjoy the financial backing or social connections of richer students once they graduate. These students need to build skills and knowledge during college if they are to use their degrees as a stepping-stone to middle-class mobility. But more privileged students must not waste this opportunity either. As recent graduates can testify, the job market isn’t kind to candidates who can’t demonstrate genuine competence, along with a well-cultivated willingness to work hard. Nor is the global economy forgiving of an American workforce with increasingly weak literacy, math and science abilities. College graduates will still fare better than those with only a high school education, of course. But a university degree unaccompanied by a gain in knowledge or skills is an empty achievement indeed. For students who have been coasting through college, and for American universities that have been demanding less work, offering more attractions and charging higher tuition, the party may soon be over. What does the author suggest in the last paragraph

A．American higher education has lost its global competitiveness.
B．People should not expect too much from American higher education.
C．The current situation in American higher education may not last long.
D．It will take a long time to change the current trend in higher education

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6.单项选择题Passage One Questions 56 to 60 are based on the following passage. One hundred years ago, "Colored" was the typical way of referring to Americans of African descent. Twenty years later, it was purposefully dropped to make way for "Negro." By the late 1960s, that term was overtaken by "Black." And then, at a press conference in Chicago in 1988, Jesse Jackson declared that "African American" was the term to embrace. This one was chosen because it echoed the labels of groups, such as "Italian Americans" and "Irish Americans," that had already been freed of widespread discrimination. A century’s worth of calculated name changes point to the fact that naming any group is a politically freighted exercise. A 2001 study cataloged all the ways in which the term "Black" carried connotations (涵义) that were more negative than those of "African American." But if it was known that "Black" people were viewed differently from "African Americans," researchers, until now, hadn’t identified what that gap in perception was derived from. A recent study, conducted by Emory University’s Erika Hall, found that "Black" people are viewed more negatively than "African Americans" because of a perceived difference in socioeconomic status. As a result, "Black" people are thought of as less competent and as having colder personalities. The study’s most striking findings shed light on the racial biases permeating the professional world. Even seemingly harmless details on a resume, it appears, can tap into recruiters’ biases. A job application might mention affiliations with groups such as the "Wisconsin Association of African-American Lawyers" or the "National Black Employees Association," the names of which apparently have consequences, and are also beyond their members’ control. In one of the study’s experiments, subjects were given a brief description of a man from Chicago with the last name Williams. To one group, he was identified as "African-American," and another was told he was "Black." With little else to go on, they were asked to estimate Mr. Williams’s salary, professional standing, and educational background. The "African-American" group estimated that he earned about $ 37 000 a year and had a two-year college degree. The "Black" group, on the other hand, put his salary at about $ 29 000, and guessed that he had only "some" college experience. Nearly three-quarters of the first group guessed that Mr. Williams worked at a managerial level, while only 38.5 percent of the second group thought so. Hall’s findings suggest there’s an argument to be made for electing to use "African American," though one can’t help but get the sense that it’s a decision that papers over the urgency of continued progress. Perhaps a new phrase is needed, one that can bring everyone one big step closer to realizing Du Bois’s original, idealistic hope: "It’s not the name-it’s the Thing that counts. " What is Dr. Du Bois’s ideal

A．All Americans enjoy equal rights.
B．A person is judged by their worth.
C．A new term is created to address African Americans.
D．All ethnic groups share the nation’s continued progress.

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7.单项选择题Passage One Questions 56 to 60 are based on the following passage. One hundred years ago, "Colored" was the typical way of referring to Americans of African descent. Twenty years later, it was purposefully dropped to make way for "Negro." By the late 1960s, that term was overtaken by "Black." And then, at a press conference in Chicago in 1988, Jesse Jackson declared that "African American" was the term to embrace. This one was chosen because it echoed the labels of groups, such as "Italian Americans" and "Irish Americans," that had already been freed of widespread discrimination. A century’s worth of calculated name changes point to the fact that naming any group is a politically freighted exercise. A 2001 study cataloged all the ways in which the term "Black" carried connotations (涵义) that were more negative than those of "African American." But if it was known that "Black" people were viewed differently from "African Americans," researchers, until now, hadn’t identified what that gap in perception was derived from. A recent study, conducted by Emory University’s Erika Hall, found that "Black" people are viewed more negatively than "African Americans" because of a perceived difference in socioeconomic status. As a result, "Black" people are thought of as less competent and as having colder personalities. The study’s most striking findings shed light on the racial biases permeating the professional world. Even seemingly harmless details on a resume, it appears, can tap into recruiters’ biases. A job application might mention affiliations with groups such as the "Wisconsin Association of African-American Lawyers" or the "National Black Employees Association," the names of which apparently have consequences, and are also beyond their members’ control. In one of the study’s experiments, subjects were given a brief description of a man from Chicago with the last name Williams. To one group, he was identified as "African-American," and another was told he was "Black." With little else to go on, they were asked to estimate Mr. Williams’s salary, professional standing, and educational background. The "African-American" group estimated that he earned about $ 37 000 a year and had a two-year college degree. The "Black" group, on the other hand, put his salary at about $ 29 000, and guessed that he had only "some" college experience. Nearly three-quarters of the first group guessed that Mr. Williams worked at a managerial level, while only 38.5 percent of the second group thought so. Hall’s findings suggest there’s an argument to be made for electing to use "African American," though one can’t help but get the sense that it’s a decision that papers over the urgency of continued progress. Perhaps a new phrase is needed, one that can bring everyone one big step closer to realizing Du Bois’s original, idealistic hope: "It’s not the name-it’s the Thing that counts. " What does Erika Hall find in her experiment about a man with the last name Williams

A．African Americans fare better than many other ethnic groups.
B．Black people’s socioeconomic status in America remains low.
C．People’s conception of a person has much to do with the way he or she is labeled.
D．One’s professional standing and income are related to their educational background.

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8.单项选择题Passage Two Questions 61 to 65 are based on the following passage. Across the board, American colleges and universities are not doing a very good job of preparing their students for the workplace or their post-graduation lives. This was made clear by the work of two sociologists, Richard Arum and Josipa Roksa. In 2011 they released a landmark study titled "Academically Adrift," which documented the lack of intellectual growth experienced by many people enrolled in college. In particular, Arum and Roksa found, college students were not developing the critical thinking, analytic reasoning and other higher-level skills that are necessary to thrive in today’s knowledge-based economy and to lead our nation in a time of complex challenges and dynamic change. Arum and Roksa placed the blame for students’ lack of learning on a watered-down college curriculum and lowered undergraduate work standards. Although going to college is supposed to be a full-time job, students spent, on average, only 12 to 14 hours a week studying and many were skating through their semesters without doing a significant amount of reading and writing. Students who take more challenging classes and spend more time studying do learn more. But the priorities of many undergraduates are with extracurricular activities, playing sports, and partying and socializing. Laura Hamilton, the author of a study on parents who pay for college, will argue in a forthcoming book that college administrations are overly concerned with the social and athletic activities of their students. In Paying for the Party, Hamilton describes what she calls the "party pathway," which eases many students through college, helped along by various clubs that send students into the party scene and a host of easier majors. By sanctioning this watered-down version of college, universities are "catering to the social and educational needs of wealthy students at the expense of others" who won’t enjoy the financial backing or social connections of richer students once they graduate. These students need to build skills and knowledge during college if they are to use their degrees as a stepping-stone to middle-class mobility. But more privileged students must not waste this opportunity either. As recent graduates can testify, the job market isn’t kind to candidates who can’t demonstrate genuine competence, along with a well-cultivated willingness to work hard. Nor is the global economy forgiving of an American workforce with increasingly weak literacy, math and science abilities. College graduates will still fare better than those with only a high school education, of course. But a university degree unaccompanied by a gain in knowledge or skills is an empty achievement indeed. For students who have been coasting through college, and for American universities that have been demanding less work, offering more attractions and charging higher tuition, the party may soon be over. What can be learned about the socially and financially privileged students

A．They tend to have a sense of superiority over their peers.
B．They can afford to choose easier majors in order to enjoy themselves.
C．They spend a lot of time building strong connections with businesses.
D．They can climb the social ladder even without a degree

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9.单项选择题The Impossibility of Rapid Energy Transitions A) Politicians are fond of promising rapid energy transitions. Whether it is a transition from imported to domestic oil or from coal-powered electricity production to natural-gas power plants, politicians love to talk big. Unfortunately for them (and often the taxpayers), our energy systems are a bit like an aircraft carrier: they are unbelievably expensive, they are built to last for a very long time, they have a huge amount of inertia (meaning it takes a lot of energy to set them moving), and they have a lot of momentum once they are set in motion. No matter how hard you try, you can’t turn something that large on a dime (10美分硬币), or even a few thousand dimes. B) In physics, moving objects have two characteristics relevant to understanding the dynamics of energy systems: inertia and momentum. Inertia is the resistance of objects to efforts to change their state of motion. If you try to push a boulder (大圆石), it pushes you back. Once you have started the boulder rolling, it develops momentum, which is defined by its mass and velocity. Momentum is said to be "conserved," that is, once you build it up, it has to go somewhere. So a heavy object, like a football player moving at a high speed, has a lot of momentum-that is, once he is moving, it is hard to change his state of motion. If you want to change his course, you have only a few choices: you can stop him, transferring (possibly painfully) some of his kinetic energy (动能) to your own body, or you can approach alongside and slowly apply pressure to gradually alter his course. C) But there are other kinds of momentum as well. After all, we don’t speak only of objects or people as having momentum; we speak of entire systems having momentum. Whether it’s a sports team or a presidential campaign, everybody relishes having the big momentum, because it makes them harder to stop or change direction. D) One kind of momentum is technological momentum. When a technology is deployed, its impacts reach far beyond itself. Consider the incandescent (白炽灯的) bulb, an object currently hated by many environmentalists and energy-efficiency advocates. The incandescent light bulb, invented by Thomas Edison, which came to be the symbol of inspiration, has been developed into hundreds, if not thousands, of forms. Today, a visit to a lighting store reveals a stunning array of choices. There are standard-shaped bulbs, flame-shaped bulbs, colored globe-shaped bulbs, and more. It is quite easy, with all that choice, to change a light bulb. E) But the momentum of incandescent lighting does not stop there. All of those specialized bulbs led to the building of specialized light fixtures, from the desk lamp you study by, to the ugly but beloved hand-painted Chinese lamp you inherited from your grandmother, to the ceiling fixture in your closet, to the light in your oven or refrigerator, and to the light that the dentist points at you. It is easy to change a light bulb, sure, but it is harder to change the bulb and its fixture. F) And there is more to the story, because not only are the devices that house incandescent bulbs shaped to their underlying characteristics, but rooms and entire buildings have been designed in accordance with how incandescent lighting reflects off walls and windows. G) As lighting expert Howard Brandston points out, "Generally, there are no bad light sources, only bad applications." There are some very commendable characteristics of the CFL [compact fluorescent(荧光的) light bulb], yet the selection of any light source remains inseparable from the luminaire (照明装置) that houses it, along with the space in which both are installed, and lighting requirements that need to be satisfied. The lamp, the fixture, and the room, all three must work in concert for the true benefits of end-users. If the CFL should be used for lighting a particular space, or an object within that space, the fixture must be designed to work with that lamp, and that fixture with the room. It is a symbiotic (共生的) relationship. A CFL cannot be simply installed in an incandescent fixture and then expected to produce a visual appearance that is more than washed out, foggy, and dim. The whole fixture must be replaced-light source and luminaire-and this is never an inexpensive proposition. H) And Brandston knows a thing or two about lighting, being the man who illuminated the Statue of Liberty. I) Another type of momentum we have to think about when planning for changes in our energy systems is labor-pool momentum. It is one thing to say that we are going to shift 30 percent of our electricity supply from, say, coal to nuclear power in 20 years. But it is another thing to have a supply of trained talent that could let you carry out this promise. That is because the engineers, designers, regulators, operators, and all of the other skilled people needed for the new energy industry are specialists who have to be trained first (or retrained, if they are the ones being laid off in some related industry), and education, like any other complicated endeavor, takes time. And not only do our prospective new energy workers have to be trained, they have to be trained in the right sequence. One needs the designers, and perhaps the regulators, before the builders and operators, and each group of workers in training has to know there is work waiting beyond graduation. In some cases, colleges and universities might have to change their training programs, adding another layer of difficulty. J) By far the biggest type of momentum that comes into play when it comes to changing our energy systems is economic momentum. The major components of our energy systems, such as fuel production, refining, electrical generation and distribution, are costly installations that have lengthy life spans. They have to operate for long periods of time before the costs of development have been recovered. When investors put up money to build, say, a nuclear power plant, they expect to earn that money back over the planned life of the plant, which is typically between 40 and 60 years. Some coal power plants in the United States have operated for more than 70 years! The oldest continuously operated commercial hydro-electric plant in the United States is on New York’s Hudson River, and it went into commercial service in 1898. K) As Vaclav Smil points out, "All the forecasts, plans, and anticipations cited above have failed so miserably because their authors and promoters thought the transitions they hoped to implement would proceed unlike all previous energy transitions, and that their progress could be accelerated in an unprecedented manner." L) When you hear people speaking of making a rapid transition toward any type of energy, whether it is a switch from coal to nuclear power, or a switch from gasoline-powered cars to electric cars, or even a switch from an incandescent to a fluorescent light, understanding energy system inertia and momentum can help you decide whether their plans are feasible. To change the light source is costly because you have to change the whole fixture.

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10.单项选择题The Impossibility of Rapid Energy Transitions A) Politicians are fond of promising rapid energy transitions. Whether it is a transition from imported to domestic oil or from coal-powered electricity production to natural-gas power plants, politicians love to talk big. Unfortunately for them (and often the taxpayers), our energy systems are a bit like an aircraft carrier: they are unbelievably expensive, they are built to last for a very long time, they have a huge amount of inertia (meaning it takes a lot of energy to set them moving), and they have a lot of momentum once they are set in motion. No matter how hard you try, you can’t turn something that large on a dime (10美分硬币), or even a few thousand dimes. B) In physics, moving objects have two characteristics relevant to understanding the dynamics of energy systems: inertia and momentum. Inertia is the resistance of objects to efforts to change their state of motion. If you try to push a boulder (大圆石), it pushes you back. Once you have started the boulder rolling, it develops momentum, which is defined by its mass and velocity. Momentum is said to be "conserved," that is, once you build it up, it has to go somewhere. So a heavy object, like a football player moving at a high speed, has a lot of momentum-that is, once he is moving, it is hard to change his state of motion. If you want to change his course, you have only a few choices: you can stop him, transferring (possibly painfully) some of his kinetic energy (动能) to your own body, or you can approach alongside and slowly apply pressure to gradually alter his course. C) But there are other kinds of momentum as well. After all, we don’t speak only of objects or people as having momentum; we speak of entire systems having momentum. Whether it’s a sports team or a presidential campaign, everybody relishes having the big momentum, because it makes them harder to stop or change direction. D) One kind of momentum is technological momentum. When a technology is deployed, its impacts reach far beyond itself. Consider the incandescent (白炽灯的) bulb, an object currently hated by many environmentalists and energy-efficiency advocates. The incandescent light bulb, invented by Thomas Edison, which came to be the symbol of inspiration, has been developed into hundreds, if not thousands, of forms. Today, a visit to a lighting store reveals a stunning array of choices. There are standard-shaped bulbs, flame-shaped bulbs, colored globe-shaped bulbs, and more. It is quite easy, with all that choice, to change a light bulb. E) But the momentum of incandescent lighting does not stop there. All of those specialized bulbs led to the building of specialized light fixtures, from the desk lamp you study by, to the ugly but beloved hand-painted Chinese lamp you inherited from your grandmother, to the ceiling fixture in your closet, to the light in your oven or refrigerator, and to the light that the dentist points at you. It is easy to change a light bulb, sure, but it is harder to change the bulb and its fixture. F) And there is more to the story, because not only are the devices that house incandescent bulbs shaped to their underlying characteristics, but rooms and entire buildings have been designed in accordance with how incandescent lighting reflects off walls and windows. G) As lighting expert Howard Brandston points out, "Generally, there are no bad light sources, only bad applications." There are some very commendable characteristics of the CFL [compact fluorescent(荧光的) light bulb], yet the selection of any light source remains inseparable from the luminaire (照明装置) that houses it, along with the space in which both are installed, and lighting requirements that need to be satisfied. The lamp, the fixture, and the room, all three must work in concert for the true benefits of end-users. If the CFL should be used for lighting a particular space, or an object within that space, the fixture must be designed to work with that lamp, and that fixture with the room. It is a symbiotic (共生的) relationship. A CFL cannot be simply installed in an incandescent fixture and then expected to produce a visual appearance that is more than washed out, foggy, and dim. The whole fixture must be replaced-light source and luminaire-and this is never an inexpensive proposition. H) And Brandston knows a thing or two about lighting, being the man who illuminated the Statue of Liberty. I) Another type of momentum we have to think about when planning for changes in our energy systems is labor-pool momentum. It is one thing to say that we are going to shift 30 percent of our electricity supply from, say, coal to nuclear power in 20 years. But it is another thing to have a supply of trained talent that could let you carry out this promise. That is because the engineers, designers, regulators, operators, and all of the other skilled people needed for the new energy industry are specialists who have to be trained first (or retrained, if they are the ones being laid off in some related industry), and education, like any other complicated endeavor, takes time. And not only do our prospective new energy workers have to be trained, they have to be trained in the right sequence. One needs the designers, and perhaps the regulators, before the builders and operators, and each group of workers in training has to know there is work waiting beyond graduation. In some cases, colleges and universities might have to change their training programs, adding another layer of difficulty. J) By far the biggest type of momentum that comes into play when it comes to changing our energy systems is economic momentum. The major components of our energy systems, such as fuel production, refining, electrical generation and distribution, are costly installations that have lengthy life spans. They have to operate for long periods of time before the costs of development have been recovered. When investors put up money to build, say, a nuclear power plant, they expect to earn that money back over the planned life of the plant, which is typically between 40 and 60 years. Some coal power plants in the United States have operated for more than 70 years! The oldest continuously operated commercial hydro-electric plant in the United States is on New York’s Hudson River, and it went into commercial service in 1898. K) As Vaclav Smil points out, "All the forecasts, plans, and anticipations cited above have failed so miserably because their authors and promoters thought the transitions they hoped to implement would proceed unlike all previous energy transitions, and that their progress could be accelerated in an unprecedented manner." L) When you hear people speaking of making a rapid transition toward any type of energy, whether it is a switch from coal to nuclear power, or a switch from gasoline-powered cars to electric cars, or even a switch from an incandescent to a fluorescent light, understanding energy system inertia and momentum can help you decide whether their plans are feasible. Efforts to accelerate the current energy transitions didn’t succeed as expected.

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