Ответ:

1. When I came home, my little sister was sleeping.

2. When Nick came home, his brother was playing with his toys.

3. When mother came home, I was doing my homework.

4. When father came home, Pete was sleeping.

5. When mother came home, the children were playing on the carpet.

6. When I got up, my mother and father were drinking tea.

7. When I came to my friend's place, he was watching TV.

8. When I saw my friends, they were playing.