问题补充:
—What were you doing at this time yesterday?
—I on the grass and playing with Tony.
A. sit
B. sat
C. am sitting
D. was sitting
答案:
A. sit
B. sat
C. am sitting
(答案→)D. was sitting
解析:句意:昨天的这个时间你在做什么?我在草地上坐着和Tony一起玩.过去进行时表示过去某某一时刻或过去一段时间内正在进行的动作.常用的时间状语then,at that time,this time yesterday,at ten yerterday等, 根据语境和题意故选D.