请教PREP-1-1

1.    (24179-!-item-!-188;#058&000705)

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.

(C) The mineral shungite itself contains large amounts of carbon, from which the fullerenes apparently formed.

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

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

答案是D，

可不明白B为什么错，B说明F不一定形成于地球，那就不能evaluating hypotheses about the state of the Earth's crust at the time these naturally occurring fullerenes were formed了呀

也没很明白D为什么对。。。|||

好心人帮我解答一下吧，想来想去更糊涂了。。。先谢谢了！ 

不知道B 是不是因为some 的问题呢，尽管有一些来自陨石，还有一些来自地球形成，还是可以推出其形成过程中的状态。

D 是不是因为晶体结构本身他们就不明白，所以那个东东的形成肯定也不会明白了。

我逻辑很烂，所以我也不是很肯定呢

谢谢你

我估计着也就是这原因了

唉 我逻辑也不好 头大

题目说尽管F在实验室里可以合成,也能在自然界里找到,既然实验需要不同的条件,这个发现也就给地理学家一个CASE,来评价对F自然形成时期地壳状况的预测.

破题思路:削弱

A确认需要小心做实验,无关

B是无关选项,F在陨石里发现并不能削弱结论

CS含碳,F形成

D自然形成的F的结构是未知的(因为现在是人工合成的,凭什么以人工合成的东西去评价自然界形成它的条件呢)

E无关

B肯定是错的。SOME F ALSO ..., 意思是说出了地球上其他地方发现的之外，而不是说地球上的F都是在那里发现的。

我选地D适应为其他都可以被排除。但是D然我很confused是PREVIOUSLY,意思是说以前不知道，但是现在已经知道了!

B肯定是无关选项， fullerenes 被发现在 the remains of a small meteorite  中无关选项，在哪里还能够发现fullerenes 不是这里的描述重点。我个人的意见

请教各位是如何排除C的