求助大家帮忙看看，9804sa，非常感谢

wfxmfwjwUID: 3582171

Much of the research on hallucinogenic drugs such as LSD has focused on the
neurotransmitter serotonin, a chemical that when released from a presynaptic
serotonin-secreting neuron causes the transmission of a nerve impulse across a synapse to
an adjacent postsynaptic, or target, neuron. There are two major reasons for this emphasis.
First, it was discovered early on that many of the major hallucinogens have a molecular
structure similar to that of serotonin. In addition, animal studies of brain neurochemistry
following administration of hallucinogens invariably reported changes in serotonin levels.
Early investigators correctly reasoned that the structural similarity to the serotonin
molecule might imply that LSD’s effects are brought about by an action on the
neurotransmission of serotonin in the brain. Unfortunately, the level of technical expertise in
the field of brain research was such that this hypothesis had to be tested on peripheral tissue
(tissue outside the brain). Two different groups of scientists reported that LSD powerfully
blockaded serotonin’s action. Their conclusions were quickly challenged, however. We now
know that the action of a drug at one site in the body does not necessarily correspond to the
drug’s action at another site, especially when one site is in the brain and the other is not.
By the 1960’s, technical advances permitted the direct testing of the hypothesis that LSD
and related hallucinogens act by directly suppressing the activity of serotonin-secreting
neurons themselves—the so-called presynaptic hypothesis. Researchers reasoned that if the
hallucinogenic drugs act by suppressing the activity of serotonin-secreting neurons, then
drugs administered after these neurons had been destroyed should have no effect on
behavior, because the system would already be maximally suppressed. Contrary to their
expectations, neuron destruction enhanced the effect of LSD and related hallucinogens on
behavior. Thus, hallucinogenic drugs apparently do not act directly on serotonin-secreting
neurons.
However, these and other available data do support an alternative hypothesis that LSD
and related drugs act directly at receptor sites on serotonin target neurons (the postsynaptic
hypothesis). The fact that LSD elicits “serotonin syndrome”—that is, causes the same kinds
of behaviors as does the administration of serotonin—in animals whose brains are depleted
of serotonin indicates that LSD acts directly on serotonin receptors, rather than indirectly
through the release of stores of serotonin. The enhanced effect of LSD reported after
serotonin depletion could be due to a proliferation of serotonin receptor sites on serotonin
target neurons. This phenomenon often follows neuron destruction or neurotransmitter
depletion; the increase in the number of receptor sites appears to be a compensatory
response to decreased input. Significantly, this hypothesis is supported by data from a
number of different laboratories.


The author’s attitude toward early researchers’ reasoning concerning the implications of similarities in the structures of serotonin and LSD molecules can best be described as one of
Acomplete agreeement
Breluctant support
Csubtle condescension
Dirreverent dismissal
Estrong opposition

答案选B ，但不知到哪里可以体现reluctant。

请求大神好心人帮忙指点一下，非常感谢:loveliness:

wfxmfwjwUID: 3582171

顶一下

brooksideUID: 3627142

题目问的是similarities in the structures of serotonin and LSD molecules

对应原文出现这些关键词的是第一段的几句话，摘录如下：First, it was discovered early on that many of the major hallucinogens have a molecular structure similar to that of serotonin.。。。 Early investigators correctly reasoned that the structural similarity to the serotonin molecule might imply that LSD’s effects are brought about by an action on the neurotransmission of serotonin in the brain. Unfortunately

这个句群：第一句说明了这些科学家发现了这两种结构的近似性。第二句，关于之前的科学家对这一现象的推断，作者表示了肯定。第三句，转折。指出这一推断还应该在另一个范围内检验。

这样可以看出作者对之前科学家的推断态度是复杂的，没有很强烈的支持和反对，排除除了B之外的所有选项。

这个难道是98年的考题？真题还是模考？建议楼主用更新的题做练习。

wfxmfwjwUID: 3582171

brookside 发表于 2015-6-15 23:42
题目问的是similarities in the structures of serotonin and LSD molecules

对应原文出现这些关键词的是 ...

非常感谢

这是98年国内题真题，有什么更新的题目可以推荐吗？阅读真题好像都是一些老题了

wfxmfwjwUID: 3582171

brookside 发表于 2015-6-15 23:42
题目问的是similarities in the structures of serotonin and LSD molecules

对应原文出现这些关键词的是 ...

能再问一下大神，这篇文章的后两个假设，是否也与LSD和 serotonin 的相似性相关呀？也是依据相似性的假设还是不相关的假设呢？

brooksideUID: 3627142

wfxmfwjw 发表于 2015-6-16 00:16
非常感谢

这是98年国内题真题，有什么更新的题目可以推荐吗？阅读真题好像都是一些老题了

晕，随便在网上找都找不到这么古董的题目吧。。。98年？？？！！！G都改了好几次了哇，你还能找到这么古董的题目真厉害。:p

偶其实也还在备考。用的是考满分里面的陈向东的题目，才做了4套，觉得还行，可以拿来练手找感觉。你试试呗。

但是新题跟你的老题感觉是很不同的。建议你别做了。
你这篇阅读题后有五六道题目对吧？现在一篇阅读哪里还有这么多题目？同一篇阅读出两道题跟出6道题的思路是有很大差异的。建议及时止损，不要做了。

brooksideUID: 3627142

wfxmfwjw 发表于 2015-6-16 00:21
能再问一下大神，这篇文章的后两个假设，是否也与LSD和 serotonin 的相似性相关呀？也是依据相似性的假设 ...

你这样问就说明你还没做出感觉来呀 ：）
阅读题不是有人总结过吗？一定能在原文中找出直接简单的答案。如果想复杂了，错的人就肯定是你。;P

这道题答案怎么可能分布在一篇文章两个部分呢？你估计是没把文章结构理清楚。而且最后那几句话有structure相似？
不过实在觉得这个题怪异的话，就建议你放弃，这个题目答案设计不太好，我都怀疑不是真题。。。

wfxmfwjwUID: 3582171

brookside 发表于 2015-6-16 01:51
晕，随便在网上找都找不到这么古董的题目吧。。。98年？？？！！！G都改了好几次了哇，你还能找到这么古 ...

亲，你说的是陈虎平阅读36套吗？好像考满分上没有陈向东阅读

brooksideUID: 3627142

wfxmfwjw 发表于 2015-6-16 07:55
亲，你说的是陈虎平阅读36套吗？好像考满分上没有陈向东阅读

嗯 汗。。。

wfxmfwjwUID: 3582171

brookside 发表于 2015-6-16 08:17
嗯 汗。。。

嗯哪，亲，陈虎平36套好像大多是老g的阅读改编的，他只取文章的一部分和一部分题目。所以我就也做了老g的题，会有重复的。