请教一道PP2的阅读题~~

远花火UID: 3686911

The decrease in responsiveness that follows continuous stimulation (adaptation) is common to all sensory system, including olfaction. With continued exposure to chronically present ambient odors, individuals’ perception of odor intensity is greatly reduced. Moreover, these perceptual changes can be profound and durable. It is commonly reported that following extended absences from the odorous environment, reexposure may still fail to elicit perception at the original intensity.

Most research on olfactory adaptation examines relatively transient changes in stimulus detection or perceived intensity-rarely exceeding several hours and often less-but because olfactory adaptation can be produced with relatively short exposures, these durations are sufficient for investigating many parameters of the phenomenon. However, exposures to odors in natural environments often occur over far longer periods, and the resulting adaptations may differ qualitatively from short-term olfactory adaptation. For example, studies show that even brief periods of odorant stimulation produce transient reductions in receptors in the olfactory epithelium, a process termed “receptor fatigue”. Prolonged odor stimulation, however, could produce more long-lasting reductions in response, possibly involving structures higher in the central nervous system pathway.

The passage asserts which of the following about the exposures involved in the “research on olfactory adaptation”?
A The exposures are of long enough duration for researchers to investigate many aspects of olfactory adaptation
B The exposures have rarely consisted of reexposures following extended absences from the odorous environment.
C The exposures are intended to reproduce the relatively transient olfactory changes typical of exposures to odors in natural environments.
D Those exposures of relatively short duration are often insufficient to produce the phenomenon of receptor fatigue in study subjects.
E Those exposures lasting several hours produce reductions in receptors in the olfactory epithelium that are similar to the reductions caused by prolonged odor stimulation.

这道题的答案是A，定位句就是这个词所在的句子。
我知道A是对的，但是我考试的时候认为A这个表述只是作者的一个让步，作者的中心思想是short term experiment不够，prolonged odor stimulation也很重要，所以选了B，想问为什么是错的呢？
查了半天也没查到，看了magoosh的解释也只是说要定位到第二段第一句，所以来请教大家！
非常感谢！

远花火UID: 3686911

up

zhanghq00UID: 3677355

这个句子的语气明显在but后面的那个分句上。
作者强调的就是这些研究已经足够长到可以研究出想要的结果了，而后面两句是表明了中等长度和更长的情况下的一些特例，那些并不能够推翻这些结论。
虽然这样说感觉很牵强，但是应该没毛病……

xxxyw1993UID: 3675916

我对这道题也有问题 感觉正确选项里的many说得有些过了 要是说什么some倒还行

远花火UID: 3686911

zhanghq00 发表于 2016-8-12 23:00
这个句子的语气明显在but后面的那个分句上。
作者强调的就是这些研究已经足够长到可以研究出想要的结果了， ...

谢谢！我可能真的是想多了，唉~

远花火UID: 3686911

xxxyw1993 发表于 2016-8-13 10:00
我对这道题也有问题 感觉正确选项里的many说得有些过了 要是说什么some倒还行

确实那句话有说“many parameters of the phenomenon”，所以是many……
虽然后面一句就是However了，感觉好像是负面态度，但是其实就是客观的说实验有什么不足而已？