标题: 求助,caterpillar逻辑题 [打印本页] 作者: chenshuobj 时间: 2013-5-2 21:36 标题: 求助,caterpillar逻辑题 11. 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,本人做的时候在B与C之间犹豫很久,感觉这两个选项都对,一个是杀不死很多害虫,另一个是杀死很多益虫……求解 作者: simmba 时间: 2013-5-2 21:49
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?
题目定语从句限定了B不选作者: chenshuobj 时间: 2013-5-2 21:51
simmba 发表于 2013-5-2 21:49
Which of the following, if true, most strongly supports the view that it would not be advisable to t ...