GWD20-Q21~求教~

evelyn205205

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 ______.

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

答案：B。Why isn't D a correct answer？
请NN指教啦，many thx~

balapupu

文章不就是说体温和生存的关系么～和翅膀长和体积有什么关系？

nkzhengduo

argument的前提是说“Moth的飞行容易受到温度影响，低温时moth不得不停在树上因此容易受到捕食者的袭击”
从这个前提中可以得出结论---“moth的理想飞行温度与环境温度差距越大，moth越难以生存”
第二部分讲：1、大型moth飞得快所以容易躲避捕食者
           2、但是他们却有更高的理想飞行温度
1可以使moth生存能力加强
2有可能使moth生存能力减弱
因此答案需要剔除2的影响，使得理想飞行温度和环境温度差距尽量小，所以应当选A。

D选项有可能解释了为什么moth飞得快，却不能没有考虑温度的影响

evelyn205205

argument的前提是说“Moth的飞行容易受到温度影响，低温时moth不得不停在树上因此容易受到捕食者的袭击”
从这个前提中可以得出结论---“moth的理想飞行温度与环境温度差距越大，moth越难以生存”
第二部分讲：1、大型moth飞得快所以容易躲避捕食者
           2、但是他们却有更高的理想飞行温度
1可以使moth生存能力加强
2有可能使moth生存能力减弱
因此答案需要剔除2的影响，使得理想飞行温度和环境温度差距尽量小，所以应当选A。

D选项有可能解释了为什么moth飞得快，却不能没有考虑温度的影响

-- by 会员 nkzhengduo (2011/8/3 16:42:05)

After a serious thought, B is a answer better than A.
What do u think？

evelyn205205

文章不就是说体温和生存的关系么～和翅膀长和体积有什么关系？

-- by 会员 balapupu (2011/8/3 16:00:11)

明白了！