以下是引用elaine_tai在2005-12-10 20:48:00的发言:我支持E,理由如下: 1 我翻看了新东方的笔记,削弱是承认前提,削弱结论。 前提: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 来自不同星球细菌的蛋白质结构(长期不变)存在巨大差异,而地球上现有细菌种类之间的差异都不够大 结论:Even if bacteria did arrive on Earth from Mars, they must have died out 结论是火星细菌没来到地球上,即使来过,也都灭绝了。 2. D: It fails to consider whether all bacteria now on Earth could have arisen from transported Martian bacteria 乍看是削弱,因为如果地球现有的所有细菌都起源于(arise from)火星的细菌,那么现有细菌种类之间的差异都不够大也不能说明火星细菌没来过地球。 可是正如我在第1点中指出的,D选项主要错在与前提protein structure that would persist over time矛盾。 3. E: It fails to consider whether there could have been strains of bacteria that originated on Earth and later died out. 直接削弱结论,指出其one-sidedness。 结论说即使火星细菌到过地球,也都灭绝了。本argugment的gap就在于凭什么说即使来过,后来也都灭绝了?arguer直接假设因为地球现有细菌种类之间差异不够大,所以目前看来不可能存在外星细菌,要么就是早灭绝了,也就是说arguer直接假设现有细菌都来自地球本身。 其one-sidedness就在于我们也可以假设地球现有细菌并非来自地球。灭绝的可能是来自火星的细菌,也可能是地球上的细菌,题目中没有设定前提说火星的细菌更有可能灭绝。所以E直接指出了gap。 The argument is most vulnerable to which of the following criticisms?Of course the answer is E E少了个all,构不成削弱 即使有细菌起源于地球,然后灭亡又怎么样,还是不能排除现在地球上的细菌仍有起源于地球的。 weaken:all bacteria now on Earth have arisen from transported Martian bacteria. |