- UID
- 639873
- 在线时间
- 小时
- 注册时间
- 2011-6-13
- 最后登录
- 1970-1-1
- 主题
- 帖子
- 性别
- 保密
|
Scientists have modifi ed feed corn genetically, increasing its resistance to insect pests. Farmers who tried out the genetically modifi ed corn last season applied less insecticide to their corn fi elds and still got yields comparable to those they would have gotten with ordinary corn. Ordinary corn seed, however, costs less, and what these farmers saved on insecticide rarely exceeded their extra costs for seed. Therefore, for most feed-corn farmers, switching to genetically modifi ed seed would be unlikely to increase profi ts. Which of the following would it be most useful to know in order to evaluate the argument? (A) Whether there are insect pests that sometimes reduce feed-corn yields, but against which commonly used insecticides and the genetic modifi cation are equally ineffective (B) Whether the price that farmers receive for feed corn has remained steady over the past few years (C) Whether the insecticides typically used on feed corn tend to be more expensive than insecticides typically used on other crops (D) Whether most of the farmers who tried the genetically modifi ed corn last season applied more insecticide than was actually necessary (E) Whether, for most farmers who plant feed corn, it is their most profi table crop
作者杂文中明明说了节约杀虫剂的钱无法弥补买种子的钱,为什么还选D 我不知道是我疯了还是ETS傻了 |
|