3. ПОСТАВЬТЕ ГЛАГОЛЫ В ПРОШЕДШЕЕ ПРОДОЛЖЕННОЕ ВРЕМЯ
17. Mother (to watch) TV when he arrived. Mother was watching TV when he arrived.
18. Tom (to play) computer games at 9 pm yesterday.
19. Bob and Mark (to read) magazines when their father came.
20. She (to send) e-mails until 10 pm last night.
21. His father (to recover) in hospital for three weeks after his fall.