扫描二维码，直接登录
题库 / GMATAdvanced-CR-39
Researchers conditioned a group of flies to associate a particular odor with a weak electric shock. Twenty-four and forty-eight hours later the researchers conducted tests on the flies, both individually and in groups, to determine whether the flies retained the conditioning. When tested individually, the flies were significantly less likely to avoid areas marked with the odor. The researchers hypothesized that in the presence of the odor, a fly that retains the conditioned association gives off an alarm signal that arouses the attention of any surrounding flies, retriggering the association in them and thereby causing them to avoid the odor.
The researchers’ hypothesis requires which of the following assumptions?
The flies do not give off odors as alarm signals.
Flies that did not avoid the odor when tested individually were not merely following other flies’ movements when tested in a group.
Flies that did not avoid the odor when tested individually were less likely than the other flies to avoid the odor when tested in a group.
Prior to their conditioning, the flies would likely have found the odor used in the experiment to be pleasant.
An electric shock was used during the flies’ conditioning and during the later tests.
结论：苍蝇在团队行动时会放出信号来警示同伴
原因（实验结果）：单独的苍蝇不躲避，多只苍蝇出现躲避现象
逻辑缺陷：苍蝇在团体中的躲避行为是否由其他原因（例如只是简单模仿同伴的行动）造成，而B排除了这一个原因，C仅为重述实验结果。
选项B：取非（单纯跟着同伙一快飞），则削弱结论，即没有放出信号
C取反，那些没有avoid odor的飞飞，在有很多飞飞的时候他们会跟着别的。削弱了结论，并不是收到了信号，而是跟着别的飞。
学者假设： 苍蝇群发（give off）信号，告知其他的苍蝇oder，所以其他的苍蝇避开了
问学者的假设在什么assumption下成立？
b. 排除一个可能性- 苍蝇们（没有避开&独立实验）不会 跟着其他苍蝇走（当做群体实验时）； 取反， 苍蝇们（没有避开&独立实验）会 跟着其他苍蝇走（当做群体实验时）--> 不是因为发信号出发，而是因为跟着走，削弱
结论：在群体测验中飞走是因为收到了其他苍蝇释放的信号 削弱：不是因为收到信号，而是单纯跟着同伙一快飞
削弱：不是因为收到信号，而是单纯跟着同伙一快飞
是没读懂题，长难句
were not merely following other flies’ movements