Ответ:
1. By eight o'clock yesterday I was doing my homework and at eight I was playing the piano.
2. When I looked out of the window, the children were playing with a ball.
3. When we came to the station, the train already had left.
4. By nine o'clock yesterday grandmother was washing the dishes and at nine she was watching TV.
5. When I came home, my sister was reading a book.
6. Yesterday I found the book.
Объяснение: