题目内容
—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
D
解析:此处表示的是在说话之前的那段时间内没有专心,出现了错误,因此用过去进行时。
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题目内容
—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
D
解析:此处表示的是在说话之前的那段时间内没有专心,出现了错误,因此用过去进行时。