I called him many times but I didn’t get through maybe his mum _on the phone all the tim

问题补充：

I called him many times, but I didn’t get through, maybe his mum _on the phone all the time．

A. talked

B. was talking

C. has talked

D. had talked

答案：

A. talked

(答案→)B. was talking

C. has talked

D. had talked

解析：考查时态。句意：我一直在给她打电话，但是我打不通，也许她的妈妈一直都在打电话吗？根据句意说明是在我打电话的那段时间里他妈妈一直都在打电话，指在过去的一段时间里一直都在发生的事情，故使用过去进行时来表示。故B项正确。