How long do dolphins sleep?

How long do dolphins sleep? 海豚,dolphins,快!求How long can dolphins live?How far can a dolphin swim in a day?How fast can dolphins swim per hour?How do dolphins sleep?How long do dolphins sleep?回答,快!要准确的答案！！！！！！！！！！！！！！！！ How long can dolphins live?Are dolphins friendly?Do dolphins have a language?How long can dolphins live?How far can a dolphins swim in a day?How fast can dolphins swim per hour?How long do dolphins slep?用英语!还有一句How do dolphins sleep?还 How do dolphins sleep?英文回答, how long do you exercise every how long do you go to school how long do you read every night? how long do you love me how long do you live in japan how long do you read every night? how long do you think.怎么翻译 How long do dolphin sleep?答对有奖 How long do they stay in Beijing? 英语翻译After a long period of studies,scientists are having surprising new findings about dolphins (海豚).They6 believe that dolphins do talk to each other,whistling names among themselves and others in their group.They help one another wh How long do you do your homework every day how long sport do you do?这句话对吗?为什么? how long sport do you do?这句话对吗?为什么? 翻译：What do dolphins talk about?