I.
2 We fell asleep when we were watching TV.
3 While we were staying in London, we took a boat trip on the Thames.
4 Someone stole my bag while I was playing tennis.
5 A: Where were you going when you had an accident.
B: I was going to the sports centre.
II
2 When I phoned Sally, she didn't answer.
3 When the ball hit Toby, he started to cry.
4 When Tim heard the joke, he didn't laugh.
5 A: What did you do when you lost your passport?
B: I went to the police station.