题目内容
18、―Look! What a mistake! Why?
―Sorry, I _________ on it．
A．don’t concentrate B．hadn’t concentrated
C．haven’t been concentrating D．wasn’t concentrating
试题答案
18、D
相关题目
―Look! What a mistake! Why?
―Sorry, I _________ on it．
A．don’t concentrate B．hadn’t concentrated
C．haven’t been concentrating D．wasn’t concentrating
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