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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.
增强类-排除他因
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
结论：这个现象的原因是有fly给周围的flies发信号。
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。
if they were merely following others the experiment result does not mean that the flies give off signal
实验题： 通苍蝇在个体实验时比起集体严重更少的避免有味道的区域
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
B. Correct. Suppose that the flies that did not avoid the odor when tested individually were more likely to avoid the odor when in groups. This may be simply because these flies were following the movements of the flies that were triggered. That is, the signal did not cause the other flies' reactions. Instead, the movements of the triggered flies did. It follows that this possibility must be ruled out in order for the hypothesis to be plausible, and this answer choice does precisely that.
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
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
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.单独测试时没躲开气味的苍蝇在群组测试的时候更不容易躲开。-取反就是 单独测试没躲开的苍蝇在群组测试时候更会躲开，就加强结论，这就证明原来的是削弱结论的。所以不是C
B: 苍蝇单独的时候不会去避开那个气体；在一个群体中时不只是跟着别的苍蝇飞，（是跟随了别的苍蝇发出的信号飞）
这个flies 做了点什么 不然不能推断个体发信号给整体
单个实验时，保留这项训练的果蝇避免气味的可能性大大降低。科学家预测，在群体试验中，着了道的果蝇会发射信号给同伴，让他们避免气味。=没能回避气味的果蝇会传递信号让其他果蝇改变movement从而回避气味
cr
是没读懂题，长难句
were not merely following other flies’ movements
B. Correct. Suppose that the flies that did not avoid the odor when tested individually were more likely to avoid the odor when in groups. This may be simply because these flies were following the movements of the flies that were triggered. That is, the signal did not cause the other flies' reactions. Instead, the movements of the triggered flies did. It follows that this possibility must be ruled out in order for the hypothesis to be plausible, and this answer choice does precisely that.