Prep 1_24

qiqiusa

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

 

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.

正确答案为C

C是怎么支持了一个假设又否定了一个假设？

我感觉选B呢，B支持了第一个假设，否定了第二个假设。

chaizhi

沙发先！看了直晕

qiqiusa

求大侠来解决一下啊……

qiqiusa

没人来解决一下啊……

rnir

B对两个结论都weaken了，运动中迅速转向说明看的见，停下的频率不受上下坡影响削弱了因为要休息的可能。
Cweaken了第一个，support了第二个，虫子跑了他要停下一次才能开始加速追说明运动中可能看不见，每次停下间的时间间隔相等也是削弱了是因为体力原因停下的可能，至少相同时间内跑快跑慢消耗体力不应该完全一样吧。