求教一道GW题目，很费解啊

gumoc

Which of the following most logically completes the passage?

Each species of moth has an optimal body temperature for effective flight, and when air temperatures fall much below that temperature, the moths typically have to remain inactive on vegetation for extended periods, leaving them highly vulnerable to predators.  In general, larger moths can fly faster than smaller ones and hence have a better chance of evading flying predators, but they also have higher optimal body temperatures, which explains why ______.

large moths are generally able to maneuver better in flight than smaller moths
large moths are proportionally much more common in warm climates than in cool climates
small moths are more likely than large moths to be effectively camouflaged while on vegetation
large moths typically have wings that are larger in proportion to their body size than smaller moths do
• most predators of moths prey not only on several different species of moth but also on various species of other insects
  

求教了~~明显的不是small moth更容易隐蔽吗？
答案B  我理解的是在寒冷天气中，体温更高的BIG MOTH更少见，这个以为着BIG MOTH更容易被捕杀吗？？？

GMAT不是不考专业知识的吗？这体温高在寒冷天气下更容易被捕食者看到不是生物上的XX吗？？？

zxppx

事实上，文中根本没有谈到“谁更容易被捕杀”，“谁更会隐蔽（伪装）”
题干：
moth 都有an optimal body temperature, 当air temperature<optimal body temperature, moth变得highly vulnerable to predators.
此外，larger moths 比smaller ones fly faster and have higher optimal body temperatures
问题：根据larger moths 比smaller ones have higher optimal body temperatures可以推出什么？
因为LM比SM的体温更高，如果它们处在相同的环境下，那么显然对LM不利。所以，LM比SM 生活在更加温暖的地方，这样可以帮助LM更好生存！

gumoc

zxppx 发表于 2013-5-15 08:15
事实上，文中根本没有谈到“谁更容易被捕杀”，“谁更会隐蔽（伪装）”
题干：
moth 都有an optimal body t ...

air temperatures below that temperature推导出vulnerable to predators

这是原文给出的逻辑链，因此big moth更危险的原因：在air temperature低的时候更容易出现

受教了，我以为是他因法对原逻辑的补充说明，实际应用到题干中给出的逻辑分析。

多谢

zxppx

gumoc 发表于 2013-5-15 18:34
air temperatures below that temperature推导出vulnerable to predators

这是原文给出的逻辑链，因此bi ...

有的时候是推导出结果，有的时候是推导原因。这道题问explain why___, 显然就是推导出结果了。