Here are the sentences completed with the correct verb forms:

1. They **came** back home after they **had finished** their work.
2. She said that she **had met** Mr. Bean before.
3. Before he **went** to bed, he **read** a novel.
4. He told me he **had not worn** such kind of clothes before.
5. When I came to the stadium, the match **had started**.
6. Before she **listened** to music, she **had done** her homework.
7. Last night, Peter **went** to the supermarket before he **went** home.

Let me know if you need further assistance!