Caterpillars of all species produce an identical hormone called “juvenile hormone” that maintains feeding behavior. Only when a caterpillar has grown to the right size for pupation to take place does a special enzyme halt the production of juvenile hormone. This enzyme can be synthesized and will, on being ingested by immature caterpillars, kill them by stopping them from feeding.
Which of the following, if true, most strongly supports the view that it would not be advisable to try to eradicate agricultural pests that go through a caterpillar stage by spraying croplands with the enzyme mentioned above?
(A) Most species of caterpillar are subject to some natural predation.
(B) Many agricultural pests do not go through a caterpillar stage.
(C) Many agriculturally beneficial insects go through a caterpillar stage.
(D) Since caterpillars of different species emerge at different times, several sprayings would be necessary.
(E) Although the enzyme has been synthesized in the laboratory, no large-scale production facilities exist as yet.
答案是C，但我觉得D也可以，应为这两个选项都在说用那种方法所带来的负面影响，前者是杀死一些益虫，后者是增大消耗（several sprayings would be necessary），题目只是说'not be advisible'没有说是从哪个角度来说，如果站在cropland的角度来说C最好，应为益虫不会减少，但如果站在cropland拥有者的角度来看C和D都不错，因为这两者都增大了拥有者的消耗
希望我表达清楚了我的意思
c这个问题是必然不能实行这个计划的缺点
d这个问题只是使这个计划实施起来比较麻烦或者会有耗费 但题目里没有说会耗费多少 充其量是个小缺点 听过因为一个小缺点而否定整件计划的吗
这么说吧
c会产生不可接受的影响
d只是实施过程麻烦
不一样的
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