請教 GWD 6-Q40 感謝

saharaa

97.      (GWD 6-Q40)

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.


ANS: D  想請問E選項~~錯在哪裡?  雖然感覺D選項比較強烈~但是E感覺也有相關~~感謝大家講解~~! 多謝~~!

rudder86

題目論點: 沒有 2個細菌的特徵 是特別到足以說明 這2個細菌來自不同星球.


要 weaken 這個論點, 就是 D 選項, 細菌 可能都來自於 Mars.(源自於同一個星球)


至於 E 選項, 曾經有細菌原生在地球, 然後死光光了. 那怎麼解釋 現在的細菌? 還是來自於另一個星球?
這不就又支持了D選項?


E的論點感覺是有空缺的, 不如 D 的強烈.


所以囉~ D 吧~


Hope helps~

sbjqbS

lz已经分析的很清楚了。我稍微加点补充免得有些人还是看不太明白。

要去质疑这个理论只需要证明这一点：火星的bacteria曾经达到过地球而且现在还存活着。有两条路可以走：1）当前的bacteria都是从火星上来的 2）当前存在的bacteria部分是地球原生，部分是从火星上来的。要支持2）则需要质疑题干中的假设即不同星球上的bacteria其strain是肯定不一样的，也就是要证明火星和地球上的bacteria的strain是可以一样的。

看选项D)就是走的路1），但是没有其他选项是走路2）的。

再来看看选项E)有什么问题。

E) It fails to consider whether there could have been strains of bacteria that originated on Earth and later died out.

隐含的意思是“地球上曾经有不同strains的bacteria共存过，或者即使没有共存过那在不同阶段产生bacteria的strains可能不同”。这些可能性都无法推断出地球上的bacteria和火星上的可以有相同的strains。所以推理过程会产生断裂而无法继续。

saharaa

我还是不太明白
如果是E，就是说地球上曾经有一种bacteria和火星上来的相差的足够多，但是这种bacteria later die out
所以是能够weaken的吧
我这么想哪里不多呀，帮忙解答下呗
谢啦

gmatmba

原文意思如下：

有一些早期在火星出现的细菌随陨石进入地球，这在理论上是可行的。然而，不同星球的细菌有着相当明显的蛋白质结构差异，而且没有哪两种地球上的细菌菌株有明显到可以断定其来自其他星球的差异点。因此，即使有细菌从火星奔来地球，它们也必然挂掉了。

原文由‘地球上不存在两种在蛋白质结构上差异巨大的细菌菌株’推出先前的结论错误，即地球上的细菌不可能来自其他星球。

D项。如果地球上所有的细菌都源自火星。那么就让原材料vulnerable了。