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标题: prep1--1 [打印本页]

作者: 蜡笔小新jia 时间: 2009-4-29 17:32
标题: prep1--1

Although fullerenes--spherical molecules made entirely of carbon--were first found in the laboratory, they have since been found in nature, formed in fissures of the rare mineral shungite. Since laboratory synthesis of fullerenes requires distinctive conditions of temperature and pressure, this discovery should give geologists a test case for evaluating hypotheses about the state of the Earth's crust at the time these naturally occurring fullerenes were formed.

Which of the following, if true, most seriously undermines the argument?

(A) Confirming that the shungite genuinely contained fullerenes took careful experimentation.

(B) Some fullerenes have also been found on the remains of a small meteorite that collided with a spacecraft.

(D) The naturally occurring fullerenes are arranged in a previously unknown crystalline structure.

(E) Shungite itself is formed only under distinctive conditions.

为什么选D,不是很明白,谢谢大家了

作者: roimei 时间: 2009-6-5 14:07
请高人指教

作者: brightxray 时间: 2009-6-26 04:34
我刚开始也不大明白, 后来总算用答案想通了.

首先, 题目的conclusion: this discovery should give geologists a test case for evaluating hypotheses...
也就是说因为这个发现, 地理学家门可能可以推测出how naturally occurring fullerenes were formed.
那么我们再来看答案, D 选项说: fullerenes are arranged in a previously unknown crystalline structure, 也就是说之前的水晶结构是如何形成的, 我们并没有发现, 既然之前的成因不清楚, 地理学家肯定就没办法利用实验结果推断出how naturally occurring fullerenes were formed. 因此, D 选项削弱题目的结论.

作者: ruirui_hsu 时间: 2009-8-1 12:39

D选项的翻译是说这种天然形成的F 存在于一种前所未有的晶体结构中。

那我要是说水存在于前所未有的一个星球上的话，岂不是也不能削弱以上的结论？

作者: hughlv 时间: 2009-8-1 14:32

以下是引用ruirui_hsu在2009/8/1 12:39:00的发言：

D选项的翻译是说这种天然形成的F 存在于一种前所未有的晶体结构中。

那我要是说水存在于前所未有的一个星球上的话，岂不是也不能削弱以上的结论？

我赞成D)是最好的选项。科学家本来想通过这样的逻辑：特定的温度和压力合成人工的fullerenes，人工的fullerenes和自然产生的fullerenes完全一致，因此自然产生的fullerenes也需要特定的温度和压力。那要Weaken这个过程的最佳办法就是证明人工合成的和自然产生的并不是一样的。D)提出了这一点。

ruirui_hsu你这个问题我不知道该怎么理解能不能解释一下？“那我要是说水存在于前所未有的一个星球上的话，岂不是也不能削弱以上的结论？”

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