鱼类的身体一般呈______，表面大多______；用______呼吸；用______游泳．

看图，把句子补充完整     

A: Is          a telephone?                    A: Is         a         ?

B:        , it is.                                     B: No, it         .

A: What's          in          ?                A: May I ____ ____?

B: It's a         .                                  B: Come in, please.