Verified answer

Ответ:

1 was swimming-started

2 phoned-were playing

3 was walking-saw

4 bought-was playing

5 was watching-took

6 were flying-began

7 was making-was talking-was cleaning-were playing

8 was doing-arrived

Объяснение:

Если одно действие уже происходило, а другое появилось чуть позже, то первое выражается Past Continuous, а второе Past Simple.

Если действия одновременны, то используется Past Continuous.