| 大家说这题选什么应该?答案是D 是不是有错 
 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 to 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. |