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.

所有種類的毛毛蟲都會釋放青春期激素维持进食功能，只有当毛毛虫长到合适的大小时，可以用种特殊的酶阻止毛毛虫释放青春期激素。这酶可以合成并且被不成熟的猫猫虫消化，进而通过干扰它们的进食功能来消灭它们。

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?

哪项支持不用这种酶来消灭毛毛虫，可以expect两方面 第一酶的问题

1）酶对作物有不好的影响

2）虫子不能消灭 因为有利与作物 或者杀掉它得不偿失

A.Most species of caterpillar are subject to some natural predation.

大部分毛虫都会被受制于自然捕食。没提到 不相关

B. Many agricultural pests do not go through a caterpillar stage.

out of scope 

question is "it would NOT be advisable to try to eradicate agricultural pests that go through a caterpillar stage by spraying croplands with the enzyme "

C. Many agriculturally beneficial insects go through a caterpillar stage.

正确，这个时候的毛毛虫对作物有利。 所以不能在这个时候用这种酶杀它们

D. Since caterpillars of different species emerge at different times, several sprayings would be necessary.

true but 无关！多撒几轮跟杀不杀 无关

E. Although the enzyme has been synthesized in the laboratory, no large-scale production facilities exist as yet.

没说到large-scale这个相对概念 只要exsit就行