Mr.Liis busy _some important work in his office.nowAat b.for c,with选?why

分类: 作业答案 • 2021-12-03 21:31:12

问题描述：

答

c
这是busy的固定用法：be busy with sth.
即忙于某事
另有be busy doing sth.
即忙于做某事