How long do dolphins sleep?

How long do dolphins sleep? How do dolphins sleep? How long do dolphin sleep? How long do you sleep everynight?句形是? How long can dolphins live? 改错 How long time do you sleep every night ____ How long do you ____( sleep）every day? How long did you sleep How Do You Sleep? How Do You Sleep 歌词 选择填空（）do you sleep every day—Ten to ten．A How long B How oft How do you stop a sleep?