04 过去进行时1. 概念: 表示过去某一时刻或者某段时间正在进行或发生的动作2. 构成： 例如： I was doing my homework at this time yesterday.I was watching TV she came to see me. Tom was waiting for his sister while I was walking to the station.3. 标志词：then, at that time, this time yesterday...
