1. They were having tea when the doorbell rang.
2. I was sweeping the floor when I heard the noise.
3. A lot of children were waiting at the station when the star arrived.
4. He was having breakfast when the toaster blew up.
5. When I came into the office, my boss was waiting for me.
6. When we saw Brian, he was driving a taxi.
7. Father was waiting in the car while mother was doing the shopping.
8. When he arrived, we were having a dinner.
9. While they were playing chess, we were going shopping.
10. They were having a party while he was sleeping.
11. He took a photo when I was feeding the ducks.
12. They were playing football when the lights in the stadium went out.
13. While George and John were cleaning their room, she was doing the ironing.
14. Sam was doing the ironing when Jack phoned her.