When I came into the teacher’s office he on the phone.A. was speaking B. spoke C. had be

问题补充：

When I came into the teacher’s office, he on the phone.

A. was speaking

B. spoke

C. had been speaking

D. had spoken

答案：

(答案→)A. was speaking

B. spoke

C. had been speaking

D. had spoken

解析：考查时态。句意：当我进入教室办公室的时候，他正在接电话。根据句意说明是在我进入办公室的这个过去的时间点上正在进行的动作，故使用过去进行时。因为过去进行时可以表示在过去的一个时间点上正在进行的动作，或者表示在过去的一个时间段里所发生的事情。故A正确。