When the meeting was it was already midnight.A. at the endB. end upC. at an endD. in the

问题补充：

When the meeting was , it was already midnight.

A. at the end

B. end up

C. at an end

D. in the end

答案：

A. at the end

B. end up

(答案→)C. at an end

D. in the end

解析：短语辨析。A在…结束的时候，在…末端；B以…结束；C结束；D最后终于。句意：当会议结束的时候，已经是半夜了。根据句意说明C正确。