单项选择题
【案例分析题】
Task 2
Directions：This task is the same as Task 1.The 5questions or unfinished statements are numbered 41through 45.
A new report of the United Nations shows that，if the present growth rate of 2percent per year continues，today’s world population of 5.1billion will hit 6.4billion by the year 2000.
What’s more，the great part of the growth—9of every 10people added to the earth’s population—will be in the poor and undeveloped countries.These are the nations where providing enough food for billions of people already is proving to be a headache problem.
By the year 2000，today’s ’have not’nations will have a total population of 5billion people，nearly four fifths of the world’s population.
Food isn’t the only problem that such a population explosion presents.The more people there are and the worse their living conditions，the greater grow the possibility of all kinds of social problems.
In 1830，world population reached 1billion.It took only 100more years to add another billion to world population；just 30more to add a third billion.And it took just 15more years to reach the 4billion mark in 1975.
Actually，the world’s birth rate is falling.But so is death rate，as medical advances have made it possible for man to live longer than before.Such advances have also reduced baby death rate.Unless population growth is reduced，the world population may reach 12billion in a century.Is the earth capable of providing a good life for so large a population？
A population explosion will lead to（）.
