A popular beach has long had a dolphin feeding program in which fish are given to dolphins several times a day; many dolphins get as much as half of their food each day there. Although dolphins that first benefit from the program as adults are healthy and long-lived, their offspring have a lower life expectancy than offspring of dolphins that feed exclusively in the wild.
Which of the following, if true, most helps to explain the lower life expectancy of offspring of dolphins feeding at the beach compared to other young dolphins?
(A) Sharks that prey on dolphins are less common in the open seas off the beach than in many other areas of the open seas where dolphins congregate.
(B) Many of the adult dolphins that feed at the beach are females that nurse their offspring there.
(C) The fish given to the dolphins at the beach are the same types of fish that dolphins typically catch in the wild
(D) Many dolphins that feed at the beach with their offspring come to the beach only a few times a month.
(E) Adult dolphins that feed at the beach spend much less time teaching their offspring how to catch fish in the wild than do other adult dolphins.
觉得DE都可以。各位是从哪里判断D不对的呢?
文中的推理是说offspring自我生存能力下降,导致死亡.而D说他们来海滩的频率,不起作用
Ｄ是无关项，频率和文中的条件与结果没有任何关系。
Ｅ中的结果是生存能力下降导致原题的结果（活得时间短）
e 在海滩有鱼吃，所以不教后代捕鱼，所以死的多
d说 来海滩少，恰恰证明海滩影响不了海豚的生活方式，就解释不了为什么来海滩的后代死的多了。
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