Tony is busy-----his homework.A.doing B.do C.to do D.does
问题描述:
Tony is busy-----his homework.A.doing B.do C.to do D.does
答
Tony is busy doing his homework.
Tony正忙着做作业.
by busy doing 忙着做某事为什么要选doing。原因短语be busy doing 忙着做某事(上文打错了)by busy with 忙于某事