①Look!They{ are playing }(play)soccer.
②The children{ are swimming }(swim)in the river and they{ do }(have)have a good time.
③What{is }he{ doing }(do)now?
现在进行时结构 be+doing
①Look!They{ are playing }(play)soccer.
②The children{ are swimming }(swim)in the river and they{ do }(have)have a good time.
③What{is }he{ doing }(do)now?
现在进行时结构 be+doing