—I was at the cinema at 9 o’clock last night. What about you?—at home.A. am watching TVB.

问题补充：

—I was at the cinema at 9 o’clock last night. What about you?

—at home.

A. am watching TV

B. was watching TV

C. will watch TV

D. watched TV

答案：

A. am watching TV

(答案→)B. was watching TV

C. will watch TV

D. watched TV

解析：句意：昨晚九点钟我在电影院。你呢？结合语境可知下文描述的是过去某时正在进行的动作，故用过去进行时态。选B。