OG 11th #89

(A)          Sandactylus would not have had networks of blood vessels in the skin of its wings if these networks were of no use to Sandactylus.

(B)          All creatures that fly by flapping their wings have networks of blood vessels in the skin of their wings.

(C)          Winged dinosaurs that flapped their wings

t ,, in flight would have been able to fly more effectively than winged dinosaurs that could only glide.

(D)          If Sandactylus flew by flapping its wings, then paleontologists would certainly be able to find some evidence that it did so.

(E)          Heat generated by Sandactylus in flapping its wings in flight could not have been dispersed by anything other than the blood vessels in its wings.

本题不解为何选A，请ｎｎ帮忙解释一下！！

A is right,

Look at the bold-faced words below:

"Networks of blood vessels in bats' wings serve only to disperse heat generated in flight. This heat is generated only because bats flap their wings."  That means that the only use of the networks of blood vessels is for fly. Now the dinosaur Sandactylus had the same kind of network, what do you think? A answers the question.

在bat's的血管系统的出现是为了散热，热是由于扑腾翅膀

在Sandactylus 恐龙的翅膀里也有类似的血管系统，所以Sandactylus 这种恐龙是扑腾翅膀的，不是滑翔的

问：assumption

A：如果这样的血管系统没用是不会出现的。－－－血管就是用来散热的，散扑腾翅膀产生的热

B：所有的扑腾翅膀的动物都有这样的血管系统。－－－现在还不知道Sandactylus 是不是扑腾翅膀

C：讲Sandactylus的飞行和滑行，没有提到血管

D:： 发现Sandactylus飞行的证据，还是无关

E：同B现在还不知道Sandactylus 是不是扑腾翅膀，需要建立assumption才能成立

这里的assumption有点加强的做法

时隔很久，再问问这道题

E的解释是

Since this point is not addressed in the argument, it can not be assumed.

看不懂这句话的意思，难道是说已经承认Sandactylus flap its wings in flight？

刚才又看了一下，有点理解这句话的意思了

大概是说heat generated是不是只能被blood vessels disperse不是文中讨论的内容

这道题自己做的时候有点粗心了，结论是provide evidence for the hypothesis，我一直认为结论是hypothesis是对的。

所以看来A的正确性就完全没有问题了。

这里应该是排除他因

请众人指教：）

题干里说血管的唯一作用就是散热，也就是不散热，这些血管就没用。

把A取非，得出即使不散热，这些血管也还在，产生削弱。

 我错选B,题中fly by flapping their wings => networks of blood vessels in the skin of their wings.

反过来却不成立networks of blood vessels in the skin of their wings=*>fly by flapping their wings 

我是这样想E选项的:

将E取非:S龙拍打翅膀所产生的热可以通过血管以外的地方散发.就产生了两种可能:其一,血管不是用来散热的,而是其它地方用来散热;其二,血管和其他地方都可以散热.

若是第一种情况,则结论不成立;若是第二种情况,结论则成立.

这题很像OG202题的B选项,将人数不变取非,得到的是两种可能,有可能上升也有可能下降.

我对以下比较有争议的选项取非做个整理，请各位帮忙看思路是否正确

原文前提：Networks of blood vessels in bats' wings serve only to disperse heat generated in flight. This heat is generated only because bats flap their wings.

结论：Thus paleontologists' recent discovery that the winged dinosaur Sandactylus had similar networks of blood vessels in the skin of its wings provides evidence for the hypothesis that Sandactylus flew
            by flapping its wings, not just by gliding.

对于做这些题还是一头雾水啊...唉...看了MBZ的解释,比较容易接受,也还是有困惑的,到底这类型题该怎么做?