单选题 A new report of the United Nations shows that, if the present growth rate of 2 percent per year continues, today's world population of 5.1 billion will hit 6.4 billion by the year 2000.
What's more, the great part of the growth--9 of every 10 people 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 headachy problem.
By the year 2000, today's "have not" nations will have a total population of 5 billion 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 grows the possibility of all kinds of social problems.
In 1830, world population reached 1 billion. It took only 1 ) more years to add another billion to world population; just 30 more to add a third billion. And it took just 15 more years to reach the 4 billion 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 12 billion in a century. Is the earth capable of providing a good life for so large a population?
单选题 A population explosion will lead to ______.
  • A. a lot of social problems
  • B. medical advances
  • C. a decrease in food production
  • D. a worse life in every country
【正确答案】 A
【答案解析】[解析] 细节题。第四段提到：The more people there are and the worse their living conditions，the greater grows the possibility of all kinds of social problems．可见，人口爆炸可能导致各种社会问题。
单选题 It took years for world population to grow form 1 billion to 3 billion.
  • A. 100
  • B. 115
  • C. 130
  • D. 145
【正确答案】 C
【答案解析】[解析] 计算题。第五段提到：In 1830，world population reached 1 billion．It took only 100 more years to add another billion to world population；just 30 more to add a third billion．全世界的人口在1830年达到10亿。100年后，即1930年达到20亿，而从20亿到30亿只花了30年时间。可见，世界人口从10亿增长到30亿共经历了130年时间。
单选题 By the year 2000, today's ______ nations will have a total population of 5 billion people, nearly four fifths of the world's population.
  • A. biggest
  • B. Asian
  • C. developing
  • D. developed
【正确答案】 C
【答案解析】[解析] 细节题。见第三段：By the year 2000，today’s“have not”nations will have a total population of 5 billion people，nearly four fifths of the world’s population．到2000年，“have not”nations的人口将占世界人口的4/5。答案中与“have not”nations对应的只有developing countries，发展中国家。
单选题 ______, the world may have a population of 12 billion in a century.
  • A. If man can live longer in the future
  • B. If the science of medicine is developing fast enough
  • C. If the population growth is not reduced
  • D. If the earth is able to provide a good life for more people
【正确答案】 C
【答案解析】[解析] 细节题。文章最后一段说：Unless population growth is reduced，the world population may reach 12 billion in a century．C与原文意思最接近。
单选题 This passage tells us that ______.
  • A. the United Nations thinks it possible to avoid a population explosion
  • B. 5.1 billion people are living in the undeveloped countries
  • C. in advanced nations the population growth is being controlled
  • D. the world's population is increasing
【正确答案】 D
【答案解析】[解析] 主旨题。A的内容本文并未提到；B的后半部分叙述有误，原文是说today’s world population of 5.1 billion will hit 6.4 billion by the year 2000．可见作者写此文时，全世界的人口才51亿，而不是这51亿人都生活在不发达国家。c提到发达国家的人口增长正得到控制，而实际上是已经得到控制。通读全文，我们可知，文章传递这样一个信息：世界人口在不断增长。因此D正确。