I overslept this morning because my alarm clock .A. didn’t go outB. didn’t let outC. didn’

问题补充：

I overslept this morning because my alarm clock .

A. didn’t go out

B. didn’t let out

C. didn’t go off

D. didn’t let off

答案：

A. didn’t go out

B. didn’t let out

(答案→)C. didn’t go off

D. didn’t let off

解析：短语辨析：go out熄灭；外出；go off（警报器）突然大作; let out释放，发出；let off下车，引爆；句意：今天上午我睡过了。是因为我的闹钟没有响。根据句意说明C正确。