— Have you solved your problem?

— I’ve kept on thinking about that matter__________, but I have had no idea.

A．at times

B．some time

C．at a time

D．all the time

电缆标桩编号以（）为单位，自上行往下行方向连续编号。

A.上下部端站

B.有人增音段

C.数字段

D.无人段