prep1-4

larryhsing

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.

虽然觉得ABCD都不太对但是E好像也不太合适啊。E的意思是海滩边的大海豚花费太少的时间来教小海豚捕食，但是上文不是说many dolphins get as much as half of their food each day there，这句话隐含的信息不就是说海滩边的海豚即使不会捕食也能生存下去吗~~？

希望nn解释~~

anistonlucky

E---in response to you,many dolphins benefit from this program at first, that means it's just temporary.

then the offspings start to not used to this program, why?

because although there are lots of fish, what if the offsprings can not be able to catch them? in that case, it's equivalent to no fish.

larryhsing

好像有点想通了~多谢赐教~~