Put the verbs into Past Continuous, Past Perfect, Past Simple.
1) The Browns ... (leave) for Moscow a month ago.
2) Boys ... (ride) their bikes at 4 o'clock yesterday.
3) We ... (arrive) at the theatre before the performance ... (begin).
4) Sam ... (do) his homework from 5 to 6.
5) When I ... (phone), Ann ... already (clean) her parrot's cage.
6) The old lady ... (water) the flowers at that time.
7) Tom ... (change) his mind by that time.