1. He ________________ (knock) on the door for a long time before she let him in.
had knocked
had been knocking
has knocked
2. She _______________ (go) home by the time he arrived at the party.
had gone
had been going home
has gone
3. Paul was really exhausted because he _______________ (run) for 3 hours.
was running
has run
had been running
4. Before she found what she wanted, she _______________ (look) for a gift in many shops.
had been looking
has looked
is looking
5. When Mary went shopping, all the shops ______________ (close).
was closed
had closed
had been closing
6. Before having the accident, he ______________ (drive) for 5 hours.
is driving
has driven
had been driving