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請教一道PP

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楼主
发表于 2007-9-6 22:40:00 | 只看该作者

請教一道PP

Although fullerenes - spherical molesules 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 occuring fullerenes were formed.

Which of the follwoing, 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 occuring fullerenes are arranged in a previously unknown crystalline structure.

E. Shungite itself is formed only under distinctive conditions.

Answer : D

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