prep 1-1

timetoleave

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.

(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.

弄不清为什么是D。谢谢！

roguehsl

我试着分析一下：

实验室在一定的温度和压力条件下得到纯碳制的Ｆ，由此可以去很好的评估自然形成Ｆ时的地质状况．

Ｄ说在自然形成的Ｆ存在水晶结构，意思是说，在结构上与实验室得到的Ｆ有差别

同样的Ｆ，结构有差别，只能说明形成的环境不同，也即从实验室的温度和压力去推测自然形成Ｆ时的地质状况是不可靠的．

helen_bitw

原文：虽然F最初在实验室中发现，但是以后也在自然中发现，也就是在金属S中。

结论：既然实验室合成F需要很特别的条件，所以这个发现会给地理学家提供评估F形成的测试机会（后面这堆很复杂，又很细节，不必深究）

问题：削弱？（也就是说不能帮助地理学家评估测试F的形成）

选项：

A.确定S的确含有F要很仔细的测试（原文不是说确认有没有F这种东西，无关）

B.一些F也在流星和飞船的碰撞的残骸中产生。（超出原文范围，无关；而且，some F本身就含不确定因素，一般不正确）

C.金属S本身含有大量碳，而碳是F的形成元素。（偏离原文结论重心，对原文结论没有作用）

E.S本身也是在特殊条件下形成。（原文没说S的形成条件，与结论无关；而且，only太绝对，一般不正确）

D.自然形成的F，其结构从前不知道。（这种F和实验室里发现的F不一样，所以不能帮助地理学家测试评估；把两种F断桥，削弱）---正确

追梦爱我

LS解答的真棒

carriexu

不会呀

carriexu

buhuiya