GWD24-29

Hamburger530

Plant scientists have been able to genetically engineer vegetable seeds

to produce crops that are highly resistant to insect damage. Although

these seeds currently cost more than conventional seeds, their cost is

likely to decline. Moreover, farmers planting them can use far less pes-

ticide, and most consumers prefer vegetables grown with less pesticide,

therefore, for crops for which these seeds can be developed, their use

is likely to become the norm.



which of the following would be most useful to know in evaluating the

argument above?

     A.Whether plant scientists have developed insect-resistant seeds

For every crop that is currently grown commercially
B.Whether farmers typically use agricultural pesticides in larger

amounts than is necessary to prevent crop damage.

C.Whether plants grown from the new genetically engineered seeds

can be kept completely free of insect damage.
D.Whether seeds genetically engineered to produce insect-resistant

crops generate significantly lower per acre crop yields than do

currently used seeds.
E.Whether most varieties of crops currently grown commercially have

Greater natural resistance to insect damage than did similar vari-

eties in the past.

正确答案为D，我用排除法做的，留下了B和D，但选了B.觉得B 也很有道理，
回答是，那么可能新品种不用广泛使用。
      否，那么新品种就会广泛使用
请牛人们指点~

sdcar2012

对于B你想错了
因为无论如何 基因工程的crop比普通的要更耐虫害，原文中已经表明它所需的杀虫剂少很多：farmers planting them can use far less pesticide。因此，不管是不是原来使用的杀虫剂相对于所应该使用的过量，基因工程的crop在杀虫剂方面的花费都比普通的少。因此就这点来说，基因工程的crop更有利。

而关于杀虫剂真正要考虑的是，是否目前所种普通的crop本身就所需要的杀虫剂就非常非常少，以至于使用抗虫害的crop并没有带来多少减少杀虫剂使用量方面的好处

Hamburger530

明白了，谢谢~
我自己太马虎了。