Scientists have modified feed corn genetically, increasing its resistance to insect pests. Farmers who tried out the genetically modified corn last season applied less insecticide to their corn fields 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 modified seed would be unlikely to increase profits.
Which of the following would it be most useful to know in order to evaluate the argument?
69. Scientists have modified feed corn genetically, increasing its resistance to insect pests. Farmers who tried out the genetically modified corn last season applied less insecticide to their corn fields 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 modified seed would be unlikely to increase profits.
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 modification 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 modified corn last season applied more insecticide than was actually necessary (E) Whether, for most farmers who plant feed corn, it is their most profitable crop
此题做了两次都选得A。 OG解释:To answer a question such as this, one should look for information that would strengthen or weaken the argument. If one had information that the farmers growing the genetically modified corn could have increased their yields last year at lower cost, this would be helpful in evaluating the argument, because this would show that the argument is weak.
其实关键是看 what these farmers saved on insecticide rarely exceeded their extra costs for seed.这句话怎么理解。楼主是怎么理解的?我觉得这道题是目的题,就是评价选项能否让profit增加或者减少,D选项如果要知道,是可以确定profit的,如果超了了necessary,就是不会超过一般种子的,如果没超过,就回到如何理解上面那句话了,。。。。上面那句话我没看懂。。。