标题: OG诊断题19关于那个该死的beetle [打印本页] 作者: 2017 时间: 2011-3-22 00:11 标题: OG诊断题19关于那个该死的beetle Tiger beetles are such fast runners that they can capture virtually any nonflying insect. However, when running toward an insect, a tiger beetle will intermittently stop and then, a moment later, resume its attack. Perhaps the beetles 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 adequately 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 stops and runs away without its usual intermittent stopping. B. In pursuing a swerving insect, a beetle alters its course while running and its pauses become more frequent as the chase progress. C. In pursuing a moving insect, a beetle usually responds immediately to changes in the insect's direction, and it pauses equally frequently whether the chase is up or down an incline. D. If, when a beetle pauses, it has not gained on the insect it is pursuing, the beetle generally ends its pursuit. E. The faster a beetle pursues an insect fleeing directly away from it, the more frequently the beetle stops。 正确答案B
OG的解释： Situation： Two hypotheses are off ered to explain the sudden stop that tiger beetles make while pursuing their prey: (1) they cannot maintain the rapid pace and must rest, and (2) they run too quickly to process visual information and so temporarily go blind.
Reasoning： What point would strengthen one of the two hypotheses and weaken the other? Consider the information provided in each answer choice, remembering that information that supports one hypothesis must necessarily detract from the other. Any information that is not about pursuit or that aff ects the two hypotheses equally may be dismissed from consideration. If the frequency of stopping increases when the beetle follows a swerving insect and must constantly change its course, then the second hypothesis is strengthened; the beetle’s pauses increase as the variety of visual information that it needs to deal with increases.
B Correct. This statement provides information that strengthens the second hypothesis: the swerving pursuit and the resulting continual course adjustments appear to be forcing the beetle to stop with increasing frequency to sort out the erratic visual information.
我的想法：B正确，但理解和OG解释完全相反……我认为 a beetle alters its course while running说明beetle不需要停下来调整vision再改变course，weaken关于visual的说法； and its pauses become more frequent as the chase progress说明after chasing and running around for a while, it got tired so needed more frequent pauses to catch up its breath.
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 the next pause.
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 the next pause.
B In pursuing a swerving（突然转向的） insect, a beetle alters its course while running and its pauses become more frequent as the chase progresses. 分析B选项
在追逐突然转向的昆虫时，TB也改变了它的方向，尽管在奔跑的时候停止的频率加快了。这就是支持了解释1，而不是因为解释2.如果是解释2的话，不能够快速处理视觉信息，就不会more frequent的停下来转变方向。所以这个B支持了解释1，削弱了解释2. 作者: elusive 时间: 2016-2-17 13:07
一个解释：这个东西会停是因为累了
另一个解释：这个东西跑得太快了会间歇性失明，所以要停。