1 While Jane was walking down the street, she met John.
2 Tim went to St Peterburg last week. Befor that, he had read a lot about that wonderful city.
3 The manager was writting a letter, when I came in.
4 They hadn't travelled by plane before they went to Lake Baikal.
5 He was telling friends a frightening story when somebody knocked at the door.
6 We were pleased to see Ann again. We weren't seeing her for two years.