单选题 10. Orcas are small whales that generally travel in groups called pods. Orcas that feed on marine mammals travel in very small pods, while those that feed on fish travel in relatively large pods. Since a larger pod has an increased collective ability to locate prey, it is likely that orcas that feed on mammals travel in small pods only because the mammals that they hunt can more easily detect a large pod and escape it.
Which of the following, if true, most strongly indicates that the conclusion is too sweeping? ______

A、 Orcas that feed on fish almost always remain in the pod into which they were born, while orcas that feed on mammals will form new pods if the one they are in becomes too big.
B、 No orcas have been observed to switch back and forth between feeding on fish and feeding on mammals.
C、 Pods of orcas generally include at least one mother and one or two of her offspring.
D、 Unlike marine mammals, fish generally travel in large schools, which can provide food for large pods of orcas.
E、 Individuals from different pods interact frequently, and if pods are small, such interaction is predominantly foraging activities.

【正确答案】 A

【答案解析】 A：寻找他因。不是因为哺乳动物容易发现大鱼群，而是因为当鱼群太大时，逆戟鲸会自觉地分成小鱼群。
B：无关选项。
C：无关选项。
D：该选项讲的是以鱼类为食的逆戟鲸，而这道题讨论的是以哺乳动物为食的逆戟鲸。
E：无关选项。