昨天晚上八点，我正在做作业。

I was doing my homework at eight o'clock last night. 当妈妈回来时，爸爸正在看电视。

When mom came back, dad was watching TV. 上周六下午，他们正在公园里打篮球。

They were playing basketball in the park last Saturday afternoon. 老师进来的时候，学生们正在讨论问题。

When the teacher came in, the students were discussing questions. 那时，她正在弹钢琴。

She was playing the piano at that time. 昨天这个时候，他正在修理自行车。

He was repairing his bike at this time yesterday. 当电话响的时候，我正在洗澡。

When the phone rang, I was taking a shower. 前天傍晚，我们正在院子里聊天。

We were chatting in the yard the evening before yesterday. 雨开始下的时候，孩子们正在外面玩耍。

When the rain started, the children were playing outside. 去年夏天，我在度假的时候，每天都正在海边晒太阳。

Last summer, when I was on vacation, I was sunbathing by the sea every day. 他敲门的时候，我正在做饭。

When he knocked at the door, I was cooking. 会议开始的时候，她正在匆忙赶过来的路上。

When the meeting started, she was on her way here in a hurry. 昨天上午，工人们正在建造新房子。

The workers were building a new house yesterday morning. 我看到她的时候，她正在图书馆看书。

When I saw her, she was reading books in the library. 暴风雨来袭时，鸟儿们正在树上躲避。

When the storm came, the birds were taking shelter in the trees. 上个月这个时候，他们正在为考试做准备。

At this time last month, they were preparing for the exam. 电影开始播放时，观众们正在陆续入场。

When the movie began to play, the audience were entering the theater one after another. 爷爷讲故事的时候，小孙子正在认真听着。

When grandpa told stories, the little grandson was listening attentively. 今天早上，我路过操场时，同学们正在跑步。

This morning, when I passed by the playground, my classmates were running. 昨天下午，我正在画画，突然停电了。

Yesterday afternoon, I was drawing pictures when the power went out suddenly.