134. 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

我选的是B。我觉得农业害虫里并不只有Caterpillar。而且以前杀虫剂也不

区分益虫害虫，把杀益虫做排除感觉不充分，不能杀死害虫才是根本。

请各位帮忙分析分析。

嗯，还是我错了，有限定的为go through the Caterpillar phrase，所以B就是无关项了。

唉，速度还是太慢，现在还做不到30分钟20题；而且经常忽视关键的词。

估计还会要扩大阅读量，才能加快信息反馈的速度和准确度。