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.
Premise: 因为实验室合成的F需要在显著的温度，压力条件
Conclusion: 因此天然的F让地理学家可以验证F形成时，地壳的状况
Which of the following, if true, most seriously undermines the argument?
(A) Confirming that the shungite genuinely contained fullerenes took careful experimentation. Irrelevant
(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. ? 天然F的结构对于研究当时的地壳的状态有什么联系？
(E) Shungite itself is formed only under distinctive conditions.
答案是D，求解释作者: triangel8866 时间: 2011-12-15 21:12
The assumption of the argument is that the condition adopted by nature to make the F is the same as that used in the lab.
But if the naturally occurring F is a different form from that made in the lab, then the condition to form the naturally occurring F might be different from that to form the synthetic F. Thus, the conclusion is doubtful.作者: matchMichelle 时间: 2011-12-16 06:44
I sincerely appreciate your reply every time for answering my question ( sometimes the questions i raised are some what stupid cause i did not involve myself in deep reflection about them)
As for this one, How about choice B? I personally think B attacks the conclusion of the argument. Since the conclusion is that scientists can evaluate the state of Earth’s crust through studying the lab synthesis fullerenes. However, if some remains of the fullerenes are the products of collision between meteorites and spacecraft, therefore researchers will not get correct answer about the condition of crust at that time. (in short, B provides a possibility that some remains are not naturally occurred but are regarded so by scientists)作者: triangel8866 时间: 2011-12-16 21:18
B is irrelevant to the argument.
What the argument says is that:
1) F is synthesized in the lab.
2) F is found in nature, such as the mineral shungite.
3) Lab synthesis requires special conditions.
Conclusion: Lab synthesis of F can help geologist to
evaluating hypotheses about the state of the Earth's crust
at the time these naturally occurring fullerenes were
formed.
A) does not weaken the ARGUMENT. If F can be formed in
outerspace, great. But it does not lead to the conclusion
that the F found naturally on Earth was from the outerspace.
Pay attention to premise 2). Unless you find evidence which
says the F formed in outerspace is the F found in the
mineral shungite, the author's argument still holds. He/she
does not care about the conditions required to for F in the
outerspace. That's out of scope for the current discussion.作者: lilydenris 时间: 2011-12-17 06:54
