7. 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
Trying to make mom and pop proud
- Rep Power
B is the answer.
This is because by periodically switching the pesticide used, one can be assured that the pests will not get resistant towards a particular pesticide
and will not breed. Thus this solution is the most effective one.
- Rep Power
Problem: massive use of pesticides
Effect: 1. kills the pests natural enemies.
2. the pests become prone to a 'particular insecticide'
Ques asks: How can we increase the effectiveness of sustained used of pesticides? We can increase the effectiveness if we can reduce either effect 1 or 2 or both from occuring.
A: Using only chemically stable insecticides
We are still using insectidies and this does not explain how we can stop effects 1 & 2 from occuring.
B: Periodically switching the type of insecticide used
Well this is a good point. If we keep switching the type of insecticides used, the pests will not become prone to a 'particular insecticide'. Hence it helps in reducing effect 2. Keep this option on hold.
C: Gradually increasing the quantities of pesticides used
Again we are still using the same quantities of pesticides and the same type. So no effect.
D: Leaving a few fields fallow every year
Same as C we still use the same quantity and type of pesticides.
E: Breeding higher-yielding varieties of crop plants
Again does this help in reducing either effect 1 or 2. No. Plus its irrelevant to our discussion.
So IMO the answer should be B.
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