Put the verb in brackets into past progressive

I. Put the verb in brackets into past progressive:
  1. I (do)....... my homework when he phoned me last night.
  2. They (wait)...... for me at 7 o'clock last night.
  3. My children (play)...........  with the toys while I (prepare)...... dinner.
  4. We (talk)........ on the phone at this time yesterday.
  5. He (walk)..... home when he saw the accident.
  6. At 4 o'clock yesterday afternoon we (play)....... football in the schoolyard.
  7. It started to rain when we (watch)........ TV.
  8. When they (have)......... a drink, a waiter dropped a pile of plates.