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
Because you missed the modifiers: rarelly, necessary.
It is possible that most farmers used MORE pesticides than NECESSARY when using the new seeds. If they reduce the amount of pesticides, the cost saving would more than compensate the extra cost when buying the new seeds作者: 风行GMR 时间: 2012-2-27 18:49
