LSAT-15-2-7 need help

rongrong518

7. all zebras have stripes, and the most widespread subspecies has the best-defined stripes. The stripes must therefore be of importance to the species. Since among these grassland grazers the stripes can hardly function as camouflage, they must serve as some sort of signal for other zebras.

Which one of the following, if true, most strongly supports the conclusion regarding a signaling function?

(A) The subspecies of zebras with the best-defined strips is also characterized by exceptional size and vigor.

(B) In certain tall grasses zebras can be harder to spot than grazing animals with a coat of uniform color.

(C) A visual signal transmitted among the members of a species can consist of a temporary change of color perceptible to other members of the species.

(D) Zebras react much faster to moving shapes that have stripes than they do to moving shapes that are otherwise identical but lack stripes

(E) Zebras have a richer repertoire of vocal signals than do similar species such as horses.

the answer is D, but why not A?

in my view, exceptional size and vigor is also signalized by the strips.

need help!!

leeon

A是weaken；可能不是由strips 引起，而是size and vigor等。

D support；d说其他相同但是就是strips不同引起...。

lawyer_1

D直接支持原文结论：stripes起信号作用。A无关。其实该题为典型的原文证据对结论作用不大，直接有个结论。这种题的支持方式为直接支持结论。见连接的分析。

http://forum.chasedream.com/dispbbs.asp?boardid=24&star=2&replyid=574415&id=65598&skin=0&page=1

[此贴子已经被作者于2004-8-25 10:19:28编辑过]

leeon

不错，A是无关选项；不过我觉得这道题思路比较怪；

the stripes can hardly function as camouflage－they must serve as some sort of signal for other zebras－>The stripes must therefore be of importance to the species.

而问题问 supports the conclusion regarding a signaling function？

还有这句话Since among these grassland grazers the stripes can hardly function as camouflage放在GMAT SC中就是一个语法错误。

lawyer_1

"Since among these grassland grazers the stripes can hardly function as camouflage放在GMAT SC中就是一个语法错误。"  among在这里是in the middle of, surrounded by,并非being one of

Bensontuo

rongrong518 发表于 2004-8-25 09:04
7. all zebras have stripes, and the most widespread subspecies has the best-defined stripes. The str ...

Spot the question type -> Support the argument

Z ---> ST

ST ---> Importance of the species

ST ---> No Camouflage ---> Signal for other Z

Inference:

ST ---> No C ---> Importance of the species ---> Signal for other Z

A. Weaken

B. Not impact the argument

C. Weaken

D. Serves as the necessary assumption to back the original argument.

E. Not impact the argument.