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。 | 
