OG10-17 RC 理解不上去啊……帮忙给看看

Nanyi

Passage 17
            

Australian researchers have discovered electroreceptors

(sensory organs designed to respond to electrical fields)

clustered at the tip of the spiny anteater’s snout. The

researchers made this discovery by exposing small areas of

(5) the snout to extremely weak electrical fields and recording

the transmission of resulting nervous activity to the brain.
            

While it is true that tactile receptors, another kind of

sensory organ on the anteater’s snout, can also respond to

electrical stimuli, such receptors do so only in response to

( 10) electrical field strengths about 1,000 times
            greater than

those known to excite electroreceptors.

Having discovered the electroreceptors, researchers are

now investigating how anteaters utilize such a sophisticated

sensory system. In one behavioral experiment, researchers

(15) successfully trained an anteater to distinguish between

two troughs of water, one with a weak electrical field

and the other with none. Such evidence is
            consistent with

researchers’ hypothesis that anteaters use electroreceptors

to detect electrical signals given off by prey; however,

( 20) researchers as yet have been unable to detect electrical

signals emanating from termite mounds, where the favorite

food of anteaters live. Still, researchers have observed

anteaters breaking into a nest of ants at an oblique angle

and quickly locating nesting chambers. This ability quickly

(25)to locate unseen prey suggests, according to the researchers,

that the anteaters were using their electroreceptorsto locate

the nesting chambers.

 

102. Which of the following can be inferred about the experiment described in the first paragraph?

(A) Researchers had difficulty verifying the existence of electroreceptors in the anteater because electroreceptors respond to such a narrow range of electrical field strengths.

(B) Researchers found that the level of nervous activity in the anteater’s brain increased dramatically as the

strength of the electrical stimulus was increased.

(C) Researchers found that some areas of the anteater’s snout were not sensitive to a weak electrical stimulus.

(D) Researchers found that the anteater’s tactile receptors were more easily excited by a strong

electrical stimulus than were the electro receptors..

(E) Researchers tested small areas of the anteater’s snout in order to ensure that only electroreceptors were

responding to the stimulus.

 

不明白C是怎么推出来的？OG11上的解释说是根据文中绿色部分推出来的，我就是不明白怎么能推出not sensitive呢？
                

就是感觉这篇文章整体读得明白，但文中隐含的推理内容实在不好理解，我做得特别不好，有没有做过这题的帮给解释解释呗！

秋懿

"infer"题通常都需要根据原文做推导，楼主可根据整个第一段来推出C。

第一段的基本意思是：科学家发现食蚁兽的口鼻处的一小部分区域能感应到非常微弱的电流(这个小部分区域就是文中的"electroreceptors")；虽然在食蚁兽的口鼻处还有感觉器官(这个感应器官就是文中的"tactile receptors"),但这个感觉器官只能感受到比之前提到的电流的强度强1000倍的电流。

也就是说，除了"electroreceptors"，食蚁兽的口鼻处的其他地方都是感觉不到微弱电流的。

所以第一段其实提到了两个感觉器官："electroreceptors"&"tactile receptors"。注意文中第二句"While..."所提示的行文变化。

BTW,楼主恐怕把帖子发错地方了。哪位版主帮忙移动到RC区去。

Nanyi

非常感谢美女帮忙答疑，呵呵

我先把帖发到阅读区了，可等了一天没人理，无奈只好放这引起注意了……

还是非常感谢~~