They ______ on the program for almost one week before I joined them, and now we _____on it as no good results have come out so far.

A．had been working; are still working

B．had worked; were still working

C．have been working; have worked

D．have worked; are still working

倾斜井巷各车场应设（）室及躲避硐，并必须设挡车器或挡栏。

A.储藏

B.休息

C.信号硐