When I got home, my mother was cooking dinner.（当我到家时，我妈妈正在做晚饭。）

When the bell rang, the students rushed out of the classroom.（当铃声响起时，学生们冲出了教室。）

When she was young, she used to play the piano every day.（当她年轻时，她过去每天都弹钢琴。）

When it rains, we usually stay at home.（当下雨的时候，我们通常待在家里。）

When he arrives, we will start the meeting.（当他到达时，我们将开始会议。）

When I saw him, he was talking to a stranger.（当我看到他时，他正在和一个陌生人交谈。）

When you finish your homework, you can watch TV.（当你完成作业后，你可以看电视。）

When the sun sets, the sky turns beautiful colors.（当太阳落山时，天空变成美丽的颜色。）

When they went on vacation, they visited many interesting places.（当他们去度假时，他们参观了许多有趣的地方。）

When I grow up, I want to be a doctor.（当我长大后，我想成为一名医生。）

When the movie started, the theater became quiet.（当电影开始时，电影院变得安静。）

When she heard the news, she was very excited.（当她听到这个消息时，她非常激动。）

When we were in Paris, we ate a lot of delicious food.（当我们在巴黎时，我们吃了很多美味的食物。）

When the dog barked, I knew someone was at the door.（当狗叫时，我知道有人在门口。）

When you are tired, you should take a rest.（当你累了，你应该休息一下。）

When he lost his wallet, he felt very worried.（当他丢了钱包时，他感到非常担心。）

When the party ended, everyone said goodbye.（当派对结束时，每个人都说再见。）

When I read this book, I always think of my childhood.（当我读这本书时，我总是想起我的童年。）

When the wind blows, the leaves on the tree move.（当风吹时，树上的叶子动了。）

When you make a promise, you should keep it.（当你许下一个承诺时，你应该遵守它。）