GWD-12-Q16讨论很少

hero05

GWD-12-Q16:

Certain genetically modified strains of maize produce a natural insecticide that protects against maize-eating insects.  The insecticide occurs throughout the plant, including its pollen.  Maize pollen is dispersed by the wind and often blows onto milkweed plants that grow near maize fields.  Caterpillars of monarch butterflies feed exclusively on milkweed leaves.  When, in experiments, these caterpillars were fed milkweed leaves dusted with pollen from modified maize plants, they died.  Therefore, use of the modified maize inadvertently imperils monarch butterflies.

Which of the following, if true, most seriously weakens the argument?

A.      Per unit of volume, the natural insecticide produced by the genetically modified maize plants is less toxic to insects than are many commercial insecticides commonly used on maize plants.

B.      Standard weed-control practices that have been used by farmers for decades have largely eliminated milkweed plants from certain areas where monarch-butterfly caterpillars were once common.

C.      The experiments showed that the caterpillars were not harmed by contact with the pollen from the genetically modified plants unless they ingested it.

D.      The maize-eating insects that the natural insecticide protects against do not feed on the pollen of the maize plant.

E.       Airborne maize pollen tends to collect on the middle leaves of milkweed plants and monarch caterpillars feed only on the plant’s tender upper leaves.

问问C为什么错？

wyccnu

作者的论述，modified maize产生pollen, monarch butterflies吃了milkweed叶子上的pollen就会死，所以modified maize会影响monarch butterflies。要反对它，结点就在叶子上，而不是消化不消化pollen,所以选E. 另外我觉得C有些以偏概全，文中说的是modified maize，C说的是modified plants，当然这个不是主要原因。

仅供参考。

hero05

有道理，我觉得主要是modified plants错了吧，文中讨论的是maize.其它我觉得没问题

fogwind

以下是引用hero05在2008-12-1 8:28:00的发言：

有道理，我觉得主要是modified plants错了吧，文中讨论的是maize.其它我觉得没问题

C根本就是个无关选项，题目讨论的是 这个新品种是否对这种蝴蝶有害。这个和对蝴蝶有害的方式是通过接触或者吞食没有关系。

其它讨论看

http://forum.chasedream.com/dispbbs.asp?boardid=24&replyid=3049165&id=161135&page=1&skin=0&Star=1

caopp

我觉得b也可以理解成他因削弱，如果把结论当作因果结构的话（maize造成canterpillar die）,

而b刚好是：leave没了，canterpillar没了食物源，所以die, 完美他因削弱。

E也是完美他因削弱 把文章当作前提结论结构，Maize的insecticide只落在中间叶，而canterpillar只吃上面叶，所以不可能maize造成canterpillar die

期待NN给区别一下，怎么排出B, 看了个别人的帖子， 觉得还是没有说服我放弃B.

konell

B是加强啊，怎么削弱了？

caopp

我觉得b也可以理解成他因削弱，如果把结论当作因果结构的话（maize造成canterpillar die）,

而b刚好是：leave没了，canterpillar没了食物源，所以die, 完美他因削弱。

E也是完美他因削弱 把文章当作前提结论结构，Maize的insecticide只落在中间叶，而canterpillar只吃上面叶，所以不可能maize造成canterpillar die

期待NN给区别一下，怎么排出B, 看了个别人的帖子， 觉得还是没有说服我放弃B.

牛人给分析下

pwss

up

mars_cheung

B 是典型无关的。

题干推论是 modified maize 会造成蝴蝶的死亡。

B 是说农民通过实施 weed-control 消除了以前常有蝴蝶地方的 milkweed。 一点关系都没有啊

ponkong

恩刚做过这道题，B应该属于无关选项。