题目内容
3.The cleaners are busy _____________ Tian'anmen
Square (广场).
A. clean B. cleans
C. are cleaning D. cleaning
3. D考查固定短语。be busy doing sth"忙于做某事,,。
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题目内容
3.The cleaners are busy _____________ Tian'anmen
Square (广场).
A. clean B. cleans
C. are cleaning D. cleaning
3. D考查固定短语。be busy doing sth"忙于做某事,,。