A leading American AIDS researcher cau...

判断题A leading American AIDS researcher cautioned that public awareness，accurate statistics and participation of the non-governmental sector are critical for HIV/AIDS prevention and control in China.（）

参考答案：对

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1.单项选择题He （） himself a great deal of trouble if he had taken the advice of his lawyer last year.

A.would have saved
B.would save
C.had saved
D.would be saved

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2.单项选择题Wed better wait till December Bill （） his exam by then，so hell be able to enjoy himself.

A.will have had
B.has had
C.is going to have
D.will have

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3.单项选择题A good deal of research is being carried out nowadays （） the cause of juvenile crime.It is obvious that one of these is an unsatisfactory home background.

A.about
B.on
C.into
D.over

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4.单项选择题I should like to （）to the theater with you yesterday，but I didnt have time.

A.go
B.have
C.going
D.be

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5.The Contractor shall provide on the site in connection with the execution and completion of the Works and the remedying of any defects(). Only such technical assistants are skilled and experienced() their respective callings and such foreman and leading hand.

A、hereby
B、therein
C、in
D、as

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6.If our solar system has a Hell. it&39;s Venus. The air is choked with foul and corrosive sulfur. heaved from ancient volcanoes and feeding acid clouds above. Although the second planet is a step farther from the sunthan Mercury, a runaway greenhouse effect makes it hotter indeed. It&39;s the hottest of the nine plants, a toasty 900 degrees Fahrenheit of baking rocky flats from equator to poles. All this under a crushing atmospheric pressure 90 times that of where you&39;re sitting now. From the earthly perspective, a dead end. It must be lifeless.
"Venus has nothing," is the blunt word from planetologist Kevin Zahnle of NASA Ames Research Center in California&39;s Silicon Valley. "We&39;ve written it off. "
Yet a small group of advanced life-forms on Earth begs to differ. and theorizes that bizarre microbial ecosystems might have once populated Venus and. in fact. may be there still. Members of this loose band of researchers suggest that their colleagues have water too much on the brain, and are, in a sense, H2O chauvinists（盲目的爱国者）．
"Astrobiologists are neglecting Venus due more io narrow thinking than actual knowledge of the environment,or environments. where life can thrive." says Dirk Schulze-Makuch, a geobiologist at the University of Texas at El Paso who recently co-authored a Venus-boosting paper in Astrobiology wich colleague Louis Irwin.
The bias against life on Venus is partly rooted in our own biology. Human experience instructs that liquidwater, preferably lot of it. is essential for life. In search for extraterrestrial life, we obsess over small rivers in Mars&39; surface apparently carved by ancient gushes of water. and delight in hints of permafrost (永久冻结带) just underneath its surface. (By comparison. Venus isn&39;t even that interesting to look at:A boring cue ball (台球的白色母球) for backyard astronomers, its clouds reflects 75% of visible light.) Attention and then funding follow the water: Three more landers will depart for Mars this spring. and serious plans for sample-return missions hover in the midterm future.
"If you have limited resources, you base exploration on what you know." says Arizona State University planetary geologist Ronal Greeley. It&39;s like losing your keys on the way home al night: The first place you look is under the streetlights not because they&39;re more likely to be there. but because if they are. you’llspot them. For astrobiologists. the streetlights are the spectral (光谱的) lines for water. and they&39;ve spotted that potential on Mars, Jupiter&39;s moon Europa. even Neptune&39;s moon Triton. Not on the baking rocky flats of Venus.
测试题
Venus is the hottest of all the nine planets in the solar system because_____________.

A.it
J.many
K.it
L.greenhouse

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7.If you go down to the woods today, you may meet high-tech trees genetically modified to speed their growthor improve the quality of their wood. Genetically-engineered food crops have become increasingly common, albeit controversial. over the past ten years. But genetic engineering of trees has lagged behind.
Part of the reason is technical. Understanding. and then altering, the genes of a big pine tree are more complex than creating a better tomato. While tomatoes sprout happily, and rapidly, in the laboratory, growing a whole tree from a single, genetically altered cell in a test tube is a tricky process that takes years, not months. Moreover. little is known about tree genes. Some trees, such as pine trees. have a lot of DNA-roughly ten times as much as human. And, whereas the Human Genome Project is more than half-way throughits task of isolating and sequencing the estimated 100,00 genes in human cells. similar efforts to analyzetree genes are still just saplings (幼苗).
Given the large number of tree genes and the little that is known about them, tree engineers are starting with a search for genetic "markers". The first step is to isolate DNA from trees with desirable propertiessuch as insect resistance. The next step is to find stretches of DNA that show the presence of a particular gene. Then, when you mate two trees with different desirable properties, it is simple to check which offspring contain them all by looking for the genetic markers. Henry Amerson, at North Carolina State University, is using genetic markers to breed fungal resistance into southern pines. Billions of these are grown across America for pulp and paper, and outbreaks of disease are expensive. But not all individual trees are susceptible. Dr. Amerson’s group has found markers that distinguish fungus-resistant stock from disease-prone trees.Using traditional breeding techniques, they are introducing the resistance genes into pines on test sites in America.
Using generic markers speeds up old-fashioned breeding methods becauseyou no longer have to wait for the tree to grow up to see if it has the desiredtraits. But it is more a sophisticated form. of selective breeding. Now. however.interest in genetic tinkering (基因修补) is also gaining ground. To this end, Dr.Amerson and his colleagues are taking part in the Pine Gene Discovery Project. an initiative to identify and sequence the 50,000-odd genes in the pine tree&39;s genome. Knowing which gene does what should make it easier to know what to alter.
测试题
Compared with genetic engineering of food crops, genetic engineering of trees____________________.

A.began
I.has
J.is
K.was

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8.Women who drank three or more cups of coffee a day were 30 percent less likely to have memory decline at age 65 than whose who drank one cup or less daily. And the benefit increased with age. Women over age 80 who drank three or more cups of coffee a day were about 70 percent less likely to have memory decline than those who drank one cup or less. the researchers said.
Caffeinated tea had the same effect in the women. the study found, although more was needed to get the same caffeine boost. "Count roughly two cups of tea for a cup of coffee," said study leader Karen Ritchie of INSERM, the French National Institute for Health and Medical Research. But the researchers didn&39;t find a similarly protective effect in men, although other studies have found a benefit to males.
How might caffeine help ward off cognitive decline? "It is a cognitive stimulant." said Ritchie. It also helps to reduce levels of the protein called beta amyloid in the brain. she said. "whose accumulation is responsible for Alzheimer&39;s disease but which also occurs in normal aging."
Ritchie said she wasn&39;t sure why men in the study didn&39;t benefit from caffeine. "Our hypothesis is that either women metabolize caffeine differently than men, or there may be an interaction of the caffeine with the sex hormones.the estrogen-progesterone balance," she said.
The French study confirms previous research, said William Scott. professor of medicine at the University of Miami Miller School of Medicine. who has researched caffeine&39;s beneficial effects against Parkinson&39;s disease, also a neurodegenerative disorder.

A.
Caffeinated
B.
How
C."
D."
Ritchie
E.the
F.
The
G.
As
H.
A
I.
测试题
As
J.The
K.
B.The
L.
C.The
M.
D.The
N.

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9.According to the author. you should choose a school that____________.

A.you
B.is
C.is
D.has

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10.Early in the age of affluence（富裕）that followed World War II, an American retailing analyst named Victor Lebow proclaimed, "Our enormously productive economy... demands that we make consumption our way of life, that we convert the buying and use of goods into rituals, that we seek our spiritual satisfaction, our ego satisfaction, in consumption...We need things consumed, burned up, worn out, replaced and discarded at an ever increasing rate."

A.gave
M.gave
N.led
O.resulted

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