Prep 24 一个干扰项想不明白

jasdesky

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.

答案是C：我不是很明白啊如果这个TB每个一段时间pause一下然后再蹦哒的话，不早就被那可怜的，从stationary到flee的insect发现了嘛？这个选项到底是支持了那个解释方法呢？我觉得从C好像两个都可以解释地通啊。用"精疲力竭"法解释的话：他追不动了，于是休息一下，每休息一下力气就多一些然后就追上了。用"间歇性失明"法解释的话，每次有看见东西了然后就又去追了

为什么D不对呢？如果发现它pause的时候没有追上insect他就不追了，这不就说明了是"精疲力竭"法嘛？

另外哪位NN能告诉我B这句话啥意思啊，尤其是那个"whether the chase is up or down an incline"，瞪着看了3分钟没有明白这个选项描述什么样的动作场景

cecila

这题很诡异嘛！

OG11  Diagnostic Test 中的一道题目跟它一模一样，我当时也很头痛，所以印象深刻。

但是那里没有你的C选项，其他四个选项一样，OG中正确的选项是：

(B)   In puruing a swerving insect, a beetle alters its courseu while running and its pauses become more frequent as the chase progresses.

说了一大段总之其他各项都既不支持这也不支持那，就剩我写的这个支持视力，因为swerving了，对视力复杂了，所以多停——支持视力。你有黄书的话可以看P83页

你这里的C选项书上没有，我看看像是支持速度？间隔相等是说累了要歇；Stationary 是否定视力，静物了那么简单也照样要停。——根据黄书的复杂的那种假设倒过来想。但也不肯定，等待NN现身。

[此贴子已经被作者于2008-6-30 23:49:02编辑过]

blogfish

ding

喝咖啡的狼

Assumption 1: 累   Assumption 2 : 瞎

正确答案必须是支持一个并反对另一个，也就是要么累而不瞎，要么瞎而不累。

下面分析选项：

(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.

 respond
   immediately ：不瞎

pause equally frequently whether the chase is up or down an incline： 是说他无论上坡下坡的情况下都一个速度，说明不累

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

generally ends its pursuit：不瞎，但累不累不清楚

(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.

although when an insect that had been stationary begins to flee ：瞎，猎物都跑了，他还追

beetle increases its speed after its next pause. 还能加速，说明不累

所以只有C 是说他瞎而不累

[此贴子已经被作者于2008-7-6 17:16:23编辑过]

jasdesky

真是太精彩直白的解答了

多谢！！！

gmat_cxl

Admire楼上。

我对D的理解有点不一样，假如说beetle停下的时候，没有抓住prey insect, 就放弃：说明beetle累，但是没说瞎不瞎。当然这个理解有点吹毛求疵，并不影响选项结果。

gmat_cxl

补充：E选项因为sometimes immediately stop, 说明不瞎，但没说累不累。

sausau

??????????????????

AlienX

4th floor's explanation is excellent ;-)

zhongtanlu

喝咖啡的狼，你解释的太好了，谢谢！！