Помогите пожалуйста.
Choose the right form of the verb to complete these sentences.
1. When Susie returned home, Bob still ____________ all photos off the wall.
a. was taking b. had taken c. took
2. When Peter came to the party, the guests ____________ dinner and were dancing.
a. were finishing b. had finished c. finished
3. When there were no cars, people ____________ on foot.
a. were travelling b. had travelled c. travelled