Prep 07- 24

zhouyangweiwei

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

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

Which of thefollowing, 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 beetlethat has been chasing it, the beetle immediately turns and runs away withoutits usual intermittent stopping.

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

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

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

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

这个题目最后做错了，在选择A<B<C中间犹豫纠结了半天。最后选择了一个错误答案。正确答案是C，但我选择

说说自己的思路。
说BT这个东西run fast but they have to stop. 题干给了两种假设。1，是不能维持速度，必须停顿。2是速度太快，眼睛看不到。
选项是要找出一个支持一种假设，否定另外一种。

再来逐一读选项吧
A,，BT immediately turns and runs wasy without its usual stopping.
   我当时选了这个答案，因为它马上TURNS说明它眼睛看得到，没有stop说明否定了第一个假设
B, 也支持了两种假设，BT 马上改变方向，说明它没有BLIND的问题，and it pause frequently, that means it also strengths the first hypothese.
C, 我当时读的时候感觉这是支持了两种假设啊。

不太明白，求指点

ash1

选A的话既能够改变方向，也可以不停顿，两种假设都否定了

zhouyangweiwei

hi,  小明，非常感谢你的回复。评点得相当到位。但Ａ选项，当猎物飞过来时，bettle马上飞走，不是可以说明它的视力没有问题吗？为什么说这与题目条件不符呢？

Nathaniel-小明

【题目翻译】
甲虫飞着飞着要停有两个可能的原因，一是因为累的跑不动（体力论），二是调整视力（视力论）
【选项分析】
(A)当猎物面对beetle飞来时，beetle马上跑走，没有边飞边停。与题目条件不符
(B) 追猎物时，beetle根据猎物的位置变化马上转变（否定视力论），并且无论猎物上坡还是下坡都以一样的频率休息（否定体力论，假若支持累要休息，上坡休息应该更频繁）。此选项2个原因都否定了
(C)休息之间的时间是固定的，尽管当一只静止不动的猎物准备逃跑时，beetle在下一次休息后会加快速度。每次飞的时间固定，但是会加速，否定了体力论（若支持体力论，速度快时飞的时间应该短）。支持了视力论，beetle体力没有问题，可还是要pause，其目的就是要定位，看准了方向再加速
(D)如果当beetle休息时，它还没有赶上它追的猎物，beetle就会结束追赶。无关项
(E)当追赶过程中beetle前面有阻碍物时，beetle有时会立马停止，但是他们不会围障碍物转。无关项
【小结】
这道题的难点其实在于对题干信息、选项信息的理解，如果将大致意思翻译出来，很多问题迎刃而解。