题目信息
During the month of May, crabs arrive on Delaware's beaches to lay eggs. Certain shorebirds depend on these eggs for food during their annual spring migration to their northern breeding grounds. Delaware's crab population has declined recently. This decline, however, poses no serious threat to the migrating shorebird populations: by remaining longer in Delaware, the birds will be able to eat enough crab eggs to allow them to complete their migration.
Which of the following, if true, most seriously weakens the argument?
A:No other food available to the birds on Delaware's beaches is as nutritious and accessible as are crab eggs.
B:The decline in the number of crabs on Delaware's beaches is due to the harvesting of crabs by humans.
C:There are more crabs on Delaware's beaches than in any other area that the migrating birds pass through.
D:The crabs do not conceal their eggs.
E:The earlier in the season the shorebirds complete their migration, the more likely they are to breed successfully.
参考答案及共享解析
共享解析来源为网络权威资源、GMAT高分考生等； 如有疑问，欢迎在评论区提问与讨论
本题耗时：
已选答案：
正确答案：
E:The earlier in the season the shorebirds complete their migration, the more likely they are to breed successfully.
前提:在D 呆的越久——吃的crab egg越多——完成迁徙
结论：Crab减少——对shorebird数量没有影响
削弱——对shorebird数量有影响
A 跳出范围，other food 无关
B crab减少的原因——无关
C 无关比较，和其他地区crab数量比较
D crab不藏蛋——无关
E 正确，越早完成迁徙，繁殖成功率越高——crab减少，需要更多的时间在D，完成迁徙的时间晚，繁殖成功率低，影响数量
加入收藏
在线答疑
题目来源
GWD
