The sustained massive use of pesticides in farming has two effects that are especially pernicious.First, it often kills off the pests' natural enemies in the area.Second, it often unintentionally gives rise to insecticide-resistant pests, since those insects that survive a particular insecticide will be the ones most resistant to it, and they are the ones left to breed.
From the passage above, it can be properly inferred that the effectiveness of the sustained massive use of pesticides can be extended by doing which of the following, assuming that each is a realistic possibility?
14. The sustained massive use of pesticides in farming has two effects that are especially pernicious. First, it often kills off the pests’ natural enemies in the area. Second, it often unintentionally gives rise to insecticide-resistant pests, since those insects that survive a particular insecticide will be the ones most resistant to it, and they are the ones left to breed.
From the passage above, it can be properly inferred that the effectiveness of the sustained massive use of pesticides can be extended by doing which of the following, assuming that each is a realistic possibility?
a. Using only chemically stable insecticides
b. Periodically switching the type of insecticide used
c. Gradually increasing the quantities of pesticides used
d. Leaving a few fields fallow every year
e. Breeding higher-yielding varieties of crop plants
答案是B.
The answer believes that this rotation might allow some of the pests’ natural enemies to survive, at least until the next cycle.
Contrarily, I think it will kill more pests’natural enemies.
so I selected D instead. By leaving a few fields fallow will give both the pests and their enemies some space to respire.
My major point is "sustained effectiveness."
14. The sustained massive use of pesticides in farming has two effects that are especially pernicious. First, it often kills off the pests’ natural enemies in the area. Second, it often unintentionally gives rise to insecticide-resistant pests, since those insects that survive a particular insecticide will be the ones most resistant to it, and they are the ones left to breed.
From the passage above, it can be properly inferred that the effectiveness of the sustained massive use of pesticides can be extended by doing which of the following, assuming that each is a realistic possibility?
农药有副作用:1、杀害虫天敌;2、让虫产生抗药性。问减少副作用的办法。
逻辑链:几种solution:1、减少抗药性产生的可能;2、在抗药性之前把害虫杀掉;3、改良农药防止副作用
a. Using only chemically stable insecticides (引入新概念,错误)
b. Periodically switching the type of insecticide used (帮助solution1,正确)
c. Gradually increasing the quantities of pesticides used (对减少1和2副作用都没有帮助)
d. Leaving a few fields fallow every year (2个错误:1、没有说这些fallow field每年是否重复,所以无效,如果说leaving differernt fields fallow in different years那么效果就强一点。2、对解决副作用1有弱帮助,对副作用2没有帮助。综上不能在B/D里面排除D)
e. Breeding higher-yielding varieties of crop plants (新概念)
如果选择B, 不满足条件一(still kills of the pest natural enemies)
如果选择D, 既可以保留pests'natural enemy,又不会使pest产生抗药性.
即便看了楼上的各位解释我还是觉得D更好的满足了argument的两个条件, 关键是question stem里问的是the effectiveness of the SUSTAINED massive use of pestcides,这个sustained在这里不是指effect而是use, aka“药不能停." D在这种情况下不用考虑满不满足条件就直接OUT了