[求助]OG11th-89,麻烦哪位大侠解答一下为什么不选B

znlhy

Net works of blood vessels in bat’s wings serve only to disperse heat generated in flight. This heat is generated only because bats flap their wings. 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.

 

The argument in the passage relies on which of the following assumptions?

(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 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 could not have been dispersed by anything other than the blood vessels in its wings.
            

mbz

here you go:

http://forum.chasedream.com/dispbbs.asp?boardID=24&ID=179480&page=0

Please pay attention to level 9, his 取非 is wrong. It should be:

Not 所有会飞的生物有血管

znlhy

Thanks very much

cjyzxj

提干说：因为

1. 在bat's的血管系统的出现是为了散热，热是由于扑腾翅膀

2. 在Sandactylus 恐龙的翅膀里也有类似的血管系统，

所以：Sandactylus 这种恐龙的飞行不仅靠滑翔，还靠扑腾翅膀。

实际上，题干推理结论的过程，需要满足很多假设才能说通。其中几个假设是：

1. 如果翅膀里有血管系统，则一定是用来散热的；

2.如果翅膀需要散热，则一定是扑腾翅膀产生的；

3. 任何组织系统的存在都一定是作用的，如果没有作用，就不会存在。

在题目里，A提到了上述假设第3点。

[此贴子已经被作者于2006-9-25 11:14:07编辑过]

cx1205

以下是引用cjyzxj在2006-9-25 11:13:00的发言：

提干说：因为

1. 在bat's的血管系统的出现是为了散热，热是由于扑腾翅膀

2. 在Sandactylus 恐龙的翅膀里也有类似的血管系统，

所以：Sandactylus 这种恐龙的飞行不仅靠滑翔，还靠扑腾翅膀。

实际上，题干推理结论的过程，需要满足很多假设才能说通。其中几个假设是：

1. 如果翅膀里有血管系统，则一定是用来散热的；

2.如果翅膀需要散热，则一定是扑腾翅膀产生的；

3. 任何组织系统的存在都一定是作用的，如果没有作用，就不会存在。

在题目里，A提到了上述假设第3点。

高,实在是高,我还想问一下,你的第3个假设是不是根据only推出来的

znlhy

cjyzxj是怎么想到这几个假设的，有什么根据呢？

nuj_am

cjyzxj讲的太好了,不得不顶一下,以示尊敬!

eremitechow

类比推理的形式

A对象有属性a,b,c,d

B对象有属性a,b,c

所以B对象也有属性d

显然提干本身是一个类比推理，得出sandctylus飞行不仅靠滑翔而且靠扑腾翅膀这个结论所依赖的assumption应该是bat &　sandctylus应该具有相同或者是相类似的属性（bat有扑腾翅膀这种飞行方式）

提干中所提到bat的属性是：a.有翅膀血管系统 b.翅膀血管系统的散发扑腾翅膀产生的热 c.bat有扑腾翅膀这种飞行方式

sandctylus的属性是a.类似bat的翅膀血管系统

所以得出sandctylus飞行不仅靠滑翔而且靠扑腾翅膀(相对于bat的c属性)的结论最直接的assumption应该是sandctylus相对bat的b属性：翅膀血管系统的散发扑腾翅膀产生的热

五个选择支中并没有直接的答案，但是a选项从侧面表达了这个意思：sandctylus翅膀血管系统如果没有用那就不会不存在的，言下之意就是sandctylus翅膀血管系统的存在是为了散发扑腾翅膀产生的热量（完美的推理）