求教！GWD第四套40题

花花臭臭

It is theoretically possible that bacteria developed on Mars early in its history and that some were carried to Earth by a meteorite.However, strains of bacteria from different planets would probably have substantial differences in protein structure that would persist over time, and no two bacterial strains on Earth are different enough to have arisen on different planets.So, even if bacteria did arrive on Earth from Mars, they must have died out.



The argument is most vulnerable to which of the following criticisms?



A.It fails to establish whether bacteria actually developed on Mars.

B.It fails to establish how likely it is that Martian bacteria were transported to Earth.

C.It fails to consider whether there were means other than meteorites by which Martian bacteria could have been carried to Earth.

D.It fails to consider whether all bacteria now on Earth could have arisen from transported Martian bacteria.

E.It fails to consider whether there could have been strains of bacteria that originated on Earth and later died out.
答案是D，我不懂╮(╯▽╰)╭。谢谢大侠了！！！

hysx1988

前提：不同星球上起源的细菌即使随着时间的变迁其蛋白质结构也会有明显的不同，但是地球上上所有的细菌种类之间的区别都不足够大来证明它们起源自不同的星球。
结论：即使曾经有细菌从火星来到地球。那个细菌家族也已经灭绝。

A:细菌是否起源于火星不是我们应当讨论的额，如果没有细菌起源自火星，那前提都会被否掉，无关选项；
B:细菌怎样运到地球，无关讨论；
C：除了陨石，。有没有别的方法来到地球，同B，无关。
D:是否地球上所有细菌都来源自当初的火星细菌。如果答案是是的话，那么作者的逻辑显然是不严密的，也算是一种他因导致，即所有地球细菌的祖先都是火星细菌，因此不能因为现在地球上细菌区别不大因而说没有火星细菌来到地球。
E：是否有细菌起源地球但后来灭绝，也与讨论关系不大，主要是说有无火星细菌，该选项转移至地球细菌。

HarrisZheng

讲故事最容易理解

张三有n个儿子，如果都是一个爹生的，这n个儿子肯定都长的很像，因为这n个都长得很像，所以都是张三的儿子。

问weaken

答案： 其实这n个儿子 都是隔壁李四帮他生的

5453

一些感想~
我当时也做错了。后来发现没有关注文章的大前提：火星上的细菌被带到过地球。
按照这个理论，E选项是反前提的。 It fails to consider whether there could have been strains of bacteria that originated on Earth and later died out.该选项改变了大背景：火星上的细菌曾经被带到过地球。而直接认为地球上的细菌是原始的，是错的。

而正确选项：
It fails to consider whether all bacteria now on Earth could have arisen from transported Martian bacteria。这个选项说地球上的细菌都是火星带来的。因此没有违反文章的大前提：火星带来过细菌。 并进一步说明有可能是地球上的细菌全是火星来的。

逻辑文章的每一句话都很重要呵~ 有时候甚至是一个词。比如说有道 citizen concern serious crime和crime的题，一个serious就偷换概念了呢~~╮(╯▽╰)╭

花花臭臭

讲故事最容易理解

张三有n个儿子，如果都是一个爹生的，这n个儿子肯定都长的很像，因为这n个都长得很像，所以都是张三的儿子。

问weaken

答案： 其实这n个儿子 都是隔壁李四帮他生的

-- by 会员 HarrisZheng (2012/10/4 20:47:01)

这个解释真牛！

AnnieFFish

HarrisZheng 发表于 2012-10-4 20:47
讲故事最容易理解 张三有n个儿子，如果都是一个爹生的，这n个儿子肯定都长的很像，因为这n个都长得很像，所 ...

?  ！！！

AnnieFFish

想了想为什么E不对
It fails to consider whether there could have been strains of bacteria that originated on Earth and later died out

它只是说could have been，没有说是否所有地球上的细菌都die out
则
1. all bacteria that originated on Earth later died out --> 现存的都是来自Mars的细菌，因此才测不出不同的蛋白质 --> 所以不能得出来自MARS的细菌都die out了 .  可以削弱原文结论。
2. some bacteria that originated on Earth later died out --> 但是测不出不同的蛋白质 --> 可以推测来自MARS的细菌都die out了。
   支持了原文结论

因此E选项不行。