单选题 Where do pesticides fit into the picture of environmental disease? We have seen that they now pollute soil, water, and food, that they have the power to make our streams fishless and our gardens and woodlands silent and birdless. Man, however much he may contrary, is part of nature. Can he escape a pollution that is now so thoroughly distributed throughout our world?
We know that even single exposures to these chemicals, if the amount is large enough, can cause extremely severe poisoning. But this is not the major problem. The sudden illness or death of farmers, farm workers, and others exposed to sufficient quantities of pesticides are very sad and should not occur. For the population as a whole, we must be more concerned with the delayed effects of absorbing small amounts of the pesticides that invisibly pollute our world.
Responsible public health officials have pointed out that the biological effects of chemicals are cumulative over long periods of time, and that the danger to the individual may depend on the sum of the exposures received throughout his lifetime. For these very reasons the danger is easily ignored. It is human nature to shake off what may seem to us a threat of future disaster. "Men are naturally most impressed by diseases which have obvious signs," says a wise physician, Dr. Rene Dubos, "yet some of their worst enemies slowly approach them unnoticed."

单选题 Which of the following is closest in meaning to the sentence "Man is part of nature." (Para. 1)?

【正确答案】 B

【答案解析】[解析] 题干“Man is part of nature”即人是自然界的一部分。B项，人的行为好像他不是自然界的一部似的，即人是自然界的一部分。A项，人对自然界中发生的事情漠不关心，不合题意。C项，人可以避免环境污染的后果，不合题意。D项，人可以推卸保护环境的责任，不合题意。因此，正确答案为B。

单选题 What is the author"s attitude towards the environmental effects of pesticides?

【正确答案】 D

【答案解析】[解析] 文章第二段第二句“others exposed to sufficient quantities of pesticides are very sad and should not occur”，说明作者对杀虫剂造成的惨剧表示难过，认为这种事不该发生，因此，正确答案为D项。

单选题 In the author"s view, the sudden death caused by exposure to large amounts of pesticides ______.

A、 is not the worst of the negative consequences resulting from the use of pesticides
B、 now occurs most frequently among all accidental deaths
C、 has sharply increased so as to become the center of public attention
D、 is unavoidable because people can"t do without pesticides in farming

【正确答案】 D

【答案解析】[解析] 文章第二段，作者提到“this is not the major problem”即暴露在大量杀虫剂中而中毒并不是主要问题，这是不可避免的。对于人口整体来说，应更多地关注吸收少量杀虫剂的危害。A、B、C项并未提及，因此，正确答案为D。

单选题 People tend to ignore the delayed effects of exposure to chemicals because ______.

【正确答案】 C

【答案解析】[解析] 文章第三段倒数第二句提到，“It is human nature to shake off what may seem to us a threat of future disaster.”，人类的本性就是不理会看似在将来会造成灾难的威胁，下句又说“Men are naturally most impressed by diseases which have obvious signs”，人们自然地对那些有明显症状的疾病印象最深，即对未显现的危险，人们不会在意，因此，正确答案为C。