多选题 The population of peregrine falcons declined rapidly during the 1950's and 1960's and reached an all-time low in the early 1970's. The decline was attributed by scientists to the widespread use of the pesticide DDT in rural areas.
Which of the following, if true, gives the strongest support to the scientists claim?
  • A. DDT was not generally in use in areas devoted to heavy industry.
  • B. In the time since the use of DDT was banned in 1972, the population of peregrine falcons has been steadily increasing.
  • C. Peregrine falcons, like other birds of prey, abandon eggs that fallen out of the nest, even if the eggs remain intact.
  • D. Starling, house sparrows, and blue jays-birds the peregrine falcon prey on-were not adversely affected by DDT in their habitats.
  • E. Other birds of prey, such as the osprey, the bald cage, and the brown pclican, are found in the same area as is the peregrine falcon.
【正确答案】 B
【答案解析】[解析] 题干认为“游隼数量快速下降”这一事实,是使用DDT的原因。B选项说“自从1972年被禁用以后,游隼数量稳步增加。”没有DDT,就没有游隼数量的下降,即无因就无果。所以B选项是上述推理成立的一个假设,正确答案为B选项。