纠结这道题很久，最后在王可达老师的公共主页上找到这道题的详解，贴上来，方便跟我一样纠结的孩子们参考。
Which of the following most logically completes the argument?
The irradiation of food kills bacteria and thus retards spoilage. However, it also lowers the nutritional value of many foods. For example, irradiation destroys a significant percentage of whatever vitamin B1 a food may contain. Proponents of irradiation point out that irradiation is no worse in this respect than cooking. However, this fact is either beside the point, since much irradiated food is eaten raw, or else misleading, since _______.
A. many of the proponents of irradiation are food distributors who gain from food’s having a longer shelf life
B. it is clear that killing bacteria that may be present on food is not the only effect that irradiation has
C. cooking is usually the final step in preparing food for consumption, whereas irradiation serves to ensure a longer shelf life for perishable foods
D. certain kinds of cooking are, in fact, even more destructive of vitamin B1 than carefully controlled irradiation is
E. for food that is both irradiated and cooked, the reduction of vitamin B1 associated with either process individually is compounded
A 好多IR支持者是食物分销商，能够从食物保存时间的延长方面获益。
//分析：从动机上分析原文给出的证据是否可信，太人性了，太不GMAT了。这个属于典型无关，必须立即排除以后快。
B 杀bacteria显然不是IR的唯一效果。
//分析：不是唯一效果，那还有什么效果？好的坏的？这种混吞话很让人蛋疼。
C cooking是食物准备的最后一个步骤，而IR扮演了延长易腐烂食品的保存时间，
//分析：由已知信息里我们看不出“食物准备的步骤”跟“保存时间的延长”两者之间的关系，因此看不出cooking跟IR的这两个特点有什么可比性。最要命的是：食物准备是不是最后一个步骤跟文章说的那些摧毁维生素，杀bacteria或者降低营养价值什么的看不出直接关系。这属于典型的要求背景知识的选项。比B更糟糕。排除。
D 某些cooking的方式对于维生素B的伤害甚至大于精心控制的IR。
//分析：这似乎在说cooking不如IR好，我们原文要支持的是IR不比cooking好，因为是在IR支持者发言的转折后（however）阐述的结论。D选项虽然沾边，但是方向反了。
E 对于需要cooking和IR两个过程共同参与的食品，对于单个过程中产生的维生素B损害是叠加的。
//分析：没什么感觉。但是至少说的似乎都是原文已知信息沾边的事情，唯一的新信息是叠加的问题，这个叠加的信息跟原文的沾边程度再怎么说也比ABC强。所以只能很不情愿的选了E。至于E为什么正确，我不需要知道。
大牛们，还有个问题想问问：E选项中的for food that is both irradiated and cooked,the reduction of vitamin B1 associated with either process individually is compounded. 这句话什么意思啊？还有compounded什么意思？作者: DXDWSY 时间: 2012-10-29 21:36
