While he...,I ... the birds. *
1)fished,had watched
2)was fishing,was watching
3)had fished,had watched

We...the carpet,when the dog... *
1)cleaned,came
2)was cleaning,came
3)were cleaning,came

When I... the hall, the music... *
1)entered,was playing
2)entered,were playing
3)had entered,was playing

You...it before he... *
1)did,came
2)had done,came
3)had done,comes​