ChaseDream
搜索
返回列表 发新帖
00:00:00

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?

正确答案: D

相关帖子

更多...

更多相关帖子

524

帖子

15

好友

4712

积分

ChaseDream

注册时间
2003-03-17
精华
8
解析
查看: 2629|回复: 2
打印 上一主题 下一主题

请教prep 24179

[复制链接]
楼主
发表于 2008-8-30 03:48:00 | 只看该作者

请教prep 24179

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.

答案为什么是D?

沙发
发表于 2008-8-30 06:07:00 | 只看该作者

were first found in the laboratory, they have since been found in nature(插入语), formed in fissures of the rare mineral shungite. 说明了实验室里发现的构成fullerenes的fissures是在是石墨里的,D说自然界发现的fissures是在晶体里的,那么用合成石墨的条件来评估地壳里合成晶体的条件,自然就削弱了论断。

那个插入语容易混乱你的思维吧?

板凳
 楼主| 发表于 2008-9-16 06:00:00 | 只看该作者

真应该跟你一起学,你一点就顿开茅塞。

您需要登录后才可以回帖 登录 | 立即注册

Mark一下! 看一下! 顶楼主! 感谢分享! 快速回复:

手机版|ChaseDream|GMT+8, 2024-11-22 21:15
京公网安备11010202008513号 京ICP证101109号 京ICP备12012021号

ChaseDream 论坛

© 2003-2023 ChaseDream.com. All Rights Reserved.

返回顶部