4. The gray squirrel, introduced into local woodlands ten years ago, threatens the indigenous population of an endangered owl species, because the squirrels’ habitual stripping of tree bark destroys the trees in which the owls nest. Some local officials have advocated setting out poison for the gray squirrels. The officials argue that this
measure, while eliminating the squirrels, would pose no threat to the owl population, since the poison would be placed in containers accessible only to squirrels and other rodents.
Which one of the following, if true, most calls into question the officials’ argument?
A. One of the species whose members are likely to eat the poison is the red squirrel, a species on which owls do not prey.
B. The owls whose nesting sites are currently being destroyed by the gray squirrels feed primarily on rodents.
C. No indigenous population of any other bind species apart from the endangered owls is threatened by the gray squirrels.
D. The owls that tare threatened build their nests in the tops of trees, but the gray squirrels strip away back from the trunks.
E. The officials’ plan entails adding the poison to food sources that are usually eaten by rodents but not by other animals.
参考答案：B
思路：本题的错误在于，作者提出一种解决问题的方法，但忽略了他的副作用或反作用，从而没有从根本上解决问题或引出其他更重要的问题。
A：无关
red squirrel
B：如果rodents是owls的主要食物，那末毒死rodents将更严重的减少owls的数量。
C：无关 Here the concerned object is the owl, not the other birds
D：无关
E：无关选项
Without further information about the rodents, this choice does not bother the argument
after reading the explaination, still feel a bit strange... why the answer can be B? if the poison is work for the squirrels and some rodents (refered to the last sentence of the question), choice B seems support...
anybody help~~
怎么会suppport呢？如果毒死了owl的食物，就算是有nest，owl也活不成啊
thanks for lisy's help... remember u helped me with some other questions before..
but there is still something i am confusing..
from which sentence does the passage tell that the rodents r owl's food?
B. The owls whose nesting sites are currently being destroyed by the gray squirrels feed primarily on rodents.
from B, it tells that gray squirrels destroy owls' nesting sites. isn't it? it didn't tell that rodents or squirrels are owl's food
or does choice B implies that squirrels cause the owl's population decrease is because squirrels and owls both eat rodents? so if the poison is accessible for rodents and squirrels, the food of owls' will decrease as well?
in B," gray squirrels feed primarily on rodents. "
meaning rodents are gray squirrels food, not owls. i still don't know why B is the answer. NN help~
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