Theyarebusy________now________them

发布时间：2020-07-26 03:29:59

They are busy ________ now ________ themselves up.A.exercise; buildingB.doing sports; cheerC.exercising; to buildD.do sports; build

网友回答

C解析“忙于做某事”为be busy doing sth.表示目的用to do形式。
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