gwd-10-29

GWD-24-29.---D tricky!---the point here is not yields

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 pesticide, 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 varieties in the past.

Why is D?

The point should not be the yields, because he doesn’t say the yield in the question.

D：肯定回答，per acre 产量少，是转基因的坏处，正好是对结论中，选择转基因的weaken

否定回答，则是排除他因，support

B：far less，说明，在pesticide这方面，转基因已经少用了很多，即使，原来用的并不那么多，那也还是要比转基因多的，所以并没有什么weaken的作用

反过来，support的作用更看不出来