–What’s the noise?
–It’s the drill. Since the beginning of the term, the workers our heating system.
A. are repairing
B. have been repairing
C. will be repairing
D. repair
网友回答
A. are repairing
(答案→)B. have been repairing
C. will be repairing
D. repair
解析:可联系答.案.网客服索取。