Question

—What were you doing when I called you at 8 p.m. yesterday?  
—I      the piano at that time.

A．play

B．is playing

C．played

D．was playing

Answer 1

D

试题分析：句意：- 昨天我八点给你打电话是你在做什么？那时我正在弹钢琴。at that time在那时，过去进行时的时间标志，其结构是：were/was+doing,故选D。