[求助]请教一道PREP上的CR！！！！！！！

wenhaogsm

24.   (29155-!-item-!-188;#058&003857)
  答案是C

 

 

Tiger beetles are such fast runners that they can capture virtually any nonflying insect.  However, when running toward an insect, the beetles intermittently stop, and then, a moment later, resume their attack.  Perhaps they cannot maintain their pace and must pause for a moment's rest; but an alternative hypothesis is that while running tiger beetles are unable to process the resulting rapidly changing visual information, and so quickly go blind and stop.

 

 

Which of the following, if discovered in experiments using artificially moved prey insects, would support one of the two hypotheses and undermine the other?

 

 

(A) When a prey insect is moved directly toward a beetle that has been chasing it, the beetle immediately turns and runs away without its usual intermittent stopping.

(B) In pursuing a moving insect, the beetles usually respond immediately to changes in the insect's direction, and pause equally frequently whether the chase is up or down an incline.

(C) The beetles maintain a fixed time interval between pauses, although when an insect that had been stationary begins to flee, the beetle increases its speed after its next pause.

(D) If, when a beetle pauses, it has not gained on the insect it is pursuing, the beetle generally ends its pursuit.

(E) When an obstacle is suddenly introduced just in front of running beetles, the beetles sometimes stop immediately, but they never respond by running around the barrier.

实在是想不明白，期待NN们的解答！

万分感谢

[此贴子已经被作者于2008-10-9 16:00:20编辑过]

wenhaogsm

UP!

lesliecheung

题干中说是要不 是追的 时候体力不支要不是眼睛不能试验速度， B说改变路线后它停的 次数就多，所以呢，这就说明了 与体力无关，与视力有关， 不 知道说清楚了 没?

wenhaogsm

答案是C啊。