问题详情

In order to prove or disprove the balancing-act theory of whale migration, what question needs to be answered？

A．Whether or not whales have good eyesight

B．How long baleen whales are able to survive without food

C．How fast baleen whales can swim compared with other kinds of whales

D．Whether moving south saves whales more energy than staying north

此题为多项选择题。请帮忙给出正确答案和分析，谢谢！