Объяснение:
1.She cooked yesterday.
2. She was cooking at three o'clock yesterday.
3. She was cooking from two till four yesterday.
4. I did not read at five o'clock.
5. I was not reading when you came in.
6. What was he doing when I came?
7. He was washing his face when somebody knocked at the door.
8. Pete watered flowers in the garden yesterday.
9. When he was washing the dishes, he broke a plate.
10. What were they doing when you saw them?
11. Why were you angry with me yesterday? – I wasn't.
12. Where were you last night? – We were at the theatre.
13. When I came to the bus stop, I saw a boy who was playing with a dog.
14. It was eleven o'clock, when l decided to go to bed.
15. What time did they have dinner yesterday? – They were having dinner from seven till eight.