请教一道 gwd 上的逻辑题

lyolouhang

Which of the following most logically completes the argument?

 

The irradiation（放射） of food kills bacteria and thus retards（延迟） 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 _______.

 

1. many of the proponents of irradiation are food distributors who gain from food’s having a longer shelf life

2. it is clear that killing bacteria that may be present on food is not the only effect that irradiation has

3. cooking is usually the final step in preparing food for consumption, whereas irradiation serves to ensure a longer shelf life for perishable foods

4. certain kinds of cooking are, in fact, even more destructive of vitamin B1 than carefully controlled irradiation is

5. for food that is both irradiated and cooked, the reduction of vitamin B1 associated with either process individually is compounded

   Answer:

the answer is e, I choosed c.

天天灿烂

有问题先搜索一下前人的讨论吧。

这题的链接：

5-30 http://forum.chasedream.com/dispbbs.asp?BoardID=24&ID=77366
    

5-30 http://forum.chasedream.com/dispbbs.asp?BoardID=24&ID=74937
    

chunyuye

should be E.. The question explicitely states that "since much irradiated food is eaten raw", so the "or else" part can only refer to those not eaten raw.
E is therefore the best answer since the effect of cooking and irradiation is compounded.

C is not a good answer because both shelf life and cooking being the final step are irrelavent.