LSAT19 CR2-14

qierliu · 发表于 2003-12-9 16:20:00

14. Cafieine can kill or inhibit the growth of the larvae of several species of insects. One recent experiment showed that tobacco hornworm larvae die when they ingest a preparation that consists in part of finely powdered tea leaves which contain caffeine. This result is evidence for the hypothesis that the presence of non-negligible quantities of caffeine in various parts of many diverse species of plants is not accidental but evolved as a defense for those plants.

The argument assumes that

(A) caffeine-producing plants are an important raw material in the many facture of commercial insecticides

(B) caffeine is stored in leaves and other parts of caffeine-producing plants in concentrations roughly equal to the caffeine concentration of the preparation fed to the tobacco hornworm larvae

(C) caffeine-producing plants grow wherever insect larvae pose a major threat to indigenous plants or once posed a major threat to the ancestors of those plants

(D) the tobacco plant is among the plant species that produce caffeine for their own defense

(E) caffeine-producing plants or their ancestors have at some time been subject to being led upon by creatures sensitive to caffeine

答案是E。这个题怎么假设了呢？不太明白哦（偶比较笨的）

番茄炒蛋 · 发表于 2003-12-9 16:34:00

关键是最后一句is not accidental but evolved as a defense for those plants.
因为是作为自卫手段而产生这种功能的，那么以前就一定要被咬过咯
这就是e中说的啊
caffeine-producing plants or their ancestors have at some time been subject to being led upon by creatures sensitive to caffeine

LSAT19 CR2-14

LSAT19 CR2-14

所属分类: GMAT考试

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