新GRE小短文阅读练习题七十三
Over the last 40years there has been a great increase not only in the numberof agricultural pesticides in use but also in the care and sophistication with which
they are used by farmers.Nevertheless, the proportion of agricultural crops lost
to certain pests worldwide has increased over the same period, even when the
pests concerned have not developed resistance to existing pesticides.
Which of the following, if true, best explains how improvements in pesticide use
have been accompanied by greater losses to certain pests?
A Some dangerous but relatively ineffective pesticides common 40 years ago
are no longer in widespread use.
B As pesticides have become increasingly pest-specific, controlling certain
pests with pesticides has turned out to cost more in many cases than the
value of crop losses caused by those pests.
CBecause today's pesticides typically have more specific application condi-
tions than did pesticides in use40years ago, today's farmers observe
their fields more closely than did farmers 40years ago.
DCertain pest-control methods that some farmers use today do not involve
the use of chemical pesticides but are just as effective in eliminating insect
pests as those that do.
EForty years ago, much less was known about the effects of pesticides on
humans and other mammalian species than is now known.
答案 B
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