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标题: 求助解答一道prep的逻辑~~ [打印本页]
作者: Helloface    时间: 2010-9-21 12:08
标题: 求助解答一道prep的逻辑~~
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.  erhaps 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.

我的简短理解：甲虫飞着飞着要停有两个可能的原因，一是调整步伐，二是调整视力，问哪个是削弱一个而支持另一个的例子，答案是C，麻烦解答一下啊~~谢谢~~~=^.^=
作者: shencangbulu    时间: 2010-9-21 19:13
我觉得楼主对题义的理解是对的,看选项的话,
A如果猎物直接向正在追赶的beetle反冲过去的话,beetle立刻马上就反身就跑开了---它没停,也没blind,否则怎能马上反身就跑呢
B追赶的途中,beetle对猎物方向的变化反映迅速,在上下坡的时候会有规律地停顿---否定了视力会短暂变瞎,但没肯定它要固定调整速度啊,斜坡不代表全部啊
C在追赶过程中,它都要固定停一停,然后有猎物从静止状态突然起飞的话,beetle就会马上去追---肯定了beetle在追赶过程中是要固定停歇一下的,否定了眼前图象速度过快的时候,它会变瞎.如果会变瞎,那就不能在猎物突然起飞的情况下立刻去追了
D追不到它就不追了---无关
E如果给追赶途中的beetle突然设置障碍,有时它会突然停下,但它不会对障碍物作出反映---说了有时,所以也可以排除

写得很罗嗦,不知道这样解释你能否看懂
作者: xw909    时间: 2010-9-21 19:56
我觉得楼主对题义的理解是对的,看选项的话,
A如果猎物直接向正在追赶的beetle反冲过去的话,beetle立刻马上就反身就跑开了---它没停,也没blind,否则怎能马上反身就跑呢
B追赶的途中,beetle对猎物方向的变化反映迅速,在上下坡的时候会有规律地停顿---否定了视力会短暂变瞎,但没肯定它要固定调整速度啊,斜坡不代表全部啊
C在追赶过程中,它都要固定停一停,然后有猎物从静止状态突然起飞的话,beetle就会马上去追---肯定了beetle在追赶过程中是要固定停歇一下的,否定了眼前图象速度过快的时候,它会变瞎.如果会变瞎,那就不能在猎物突然起飞的情况下立刻去追了
D追不到它就不追了---无关
E如果给追赶途中的beetle突然设置障碍,有时它会突然停下,但它不会对障碍物作出反映---说了有时,所以也可以排除

写得很罗嗦,不知道这样解释你能否看懂
-- by 会员 shencangbulu (2010/9/21 19:13:33)


那是flee不是fly，都说了，抓不住能飞的虫子。。。。
作者: xw909    时间: 2010-9-21 20:04
是这么回事，虎虫追猎物时候要停顿，一种可能是，他跑得太快需要停顿来调整（就像开赛车，过弯要减速一样），另一种是他跑的时候眼不能处理视觉信息，也就好比是瞎子吧，（但是可不瞎，不然就没有逻辑了），需要停下来才能看到猎物的动作变化
c说他加速需要在停顿以后，就是强化了第二种，削弱了第一种，如果他可以看得清猎物，他在跑的时候就可以加速，他因为看不清，所以得等到停顿时能看清了，才能加速
作者: Helloface    时间: 2010-9-21 20:23
懂了~~谢谢各位大牛们~~提前祝中秋快乐~~~o(∩_∩)o...



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