【再发一道GWD的题~~谢谢帮助~~】

水色青空

GWD6-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.

正确答案是E，可是不太明白这道题的逻辑~希望大家帮帮忙~~

水色青空

没赶上讨论，事后诸葛亮支持D。觉得E的关键问题就是那个strains of bacteria只表示部分而不是全部。如果E改成It fails to consider whether all bacteria originated on Earth have died out.就可以和D互换了。

-- by 会员 hughlv (2010/2/17 1:23:35)

恩，建议你可以去看看楼上的那个太傻讨论，有个解释说的还比较好
个人也比较倾向D~

hughlv

没赶上讨论，事后诸葛亮支持D。觉得E的关键问题就是那个strains of bacteria只表示部分而不是全部。如果E改成It fails to consider whether all bacteria originated on Earth have died out.就可以和D互换了。

水色青空

d更好~我承认~但是唉~我知道这题有争议，看了太傻~等讨论，e是表象，d是结果，挺多人说e的也有挺多人说d的
但是我看了a大说的，也是我理解错了~你看看这个讨论贴~
http://www.taisha.org/bbs/thread-1100968-1-1.html
很详细~

-- by 会员 edwardelric (2010/2/16 19:17:41)

恩，谢谢，我会认真看的~~这题我也想了好久

张大猴

应该是d

edwardelric

d更好~我承认~但是唉~我知道这题有争议，看了太傻~等讨论，e是表象，d是结果，挺多人说e的也有挺多人说d的
但是我看了a大说的，也是我理解错了~你看看这个讨论贴~
http://www.taisha.org/bbs/thread-1100968-1-1.html
很详细~

水色青空

D可以吧，题干没有 “地球上非得有原生细菌” 的前提啊。  地球上的细菌可能都是来自火星，只是这帮土科学家觉得地球上就是有原生细菌，要查查是不是有不同，结果没查出来，就认为细菌都是地球的火星即使来也死了 这样的错误结论。

E我觉得就是说地球上有原生的，后来死了，只剩火星的了。

不同的就是用了 strain of bacteria 这个词。  

谁能解释一下怎么回事？

-- by 会员 逛来晃去 (2010/2/15 20:36:50)

我非常不好意思的说、、、、、、答案是D，我看错了~
不过文中的结论So, even if bacteria did arrive on Earth from Mars, they must have died out.

must have done表示到现在为止已经完成了，也就是到目前为止，火星的细菌也已经死了，而D只是说有可能地球上所有的细菌都起源于火星，这个貌似没有起到削弱的作用吧？

逛来晃去

D可以吧，题干没有 “地球上非得有原生细菌” 的前提啊。  地球上的细菌可能都是来自火星，只是这帮土科学家觉得地球上就是有原生细菌，要查查是不是有不同，结果没查出来，就认为细菌都是地球的火星即使来也死了 这样的错误结论。

E我觉得就是说地球上有原生的，后来死了，只剩火星的了。

不同的就是用了 strain of bacteria 这个词。  

谁能解释一下怎么回事？

sunsetchen

我看到的这道题的答案是D啊~~

edwardelric

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
理论上来讲在火星上在早期出现的细菌能够被带到地球通过行星，但是来自不同星球的细菌结构在蛋白质结构上的不同随着时间会延续的，现在地球上没有两个是不用的细菌结构，所以，即使细菌从火星上来的，他们也是一定消失了~~