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题库 / DaQuan-CR-609
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?
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.
Many of the adult dolphins that feed at the beach are females that nurse their offspring there.
The fish given to the dolphins at the beach are the same types of fish that dolphins typically catch in the wild.
Many dolphins that feed at the beach with their offspring come to the beach only a few times a month.
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.
加强，寻找二者不同
A、对比不同海域的shark
B、被投喂的成年海豚为母
C、控制被投喂/野生海豚食物变量，相似点，削弱
D、无对比
E、授人以鱼不如授人以渔，二者不同，加强
虽然成年后首次受益于该计划的海豚健康长寿，但它们的后代的预期寿命低于只在野外进食的海豚的后代。
KEY WORDS:成年后as adults才首次受益于该计划——幼时已养成野外捕食能力；只在exclusively野外进食的后代——是否也具有该能力？
off，介词表离，距离；an island off the coast of Spain 西班牙海岸附近的岛。
A，岸边的鲨鱼更少。CR：鲨鱼更少，幼仔更多，削弱。
A is exactly the opposite of what we want. It would help if there were MORE sharks near the feeding area, not fewer..
B 跟公母没关系，难道当爸爸的不管孩子了吗。
C 有吃的就挺好的了，还管吃的鱼的种类么。
D 来几次和生命健康无关
E 爸妈没教孩子怎么自然捕食，丧失技能，因为人类喂养的食物只够他们一半的量，可能吃不饱。真可怜
文中有一句话说，已成年的海豚受到了喂食的好处从而更健康长寿，A选项没有将已成年海豚与其子孙后代的关系考虑进去，并且与原文阐述信息相左。
如果是A的话，那么成年的海豚计划中的海豚怎么没有因为聚集而被鲨鱼吃掉呢？？所以A显然是不对的，因为这道题是让成年海豚计划里的海豚和幼年的相比，找出其不同点，独立第三方因素即鲨鱼不是这个不同点，如果它说小海豚容易去open sea 玩耍，成年海豚不去，所以鲨鱼吃了小海豚，这样才算不同点，但文中显然没有指出登录 或 注册 后可以参加讨论