Here are the verbs in the correct form (past perfect or past perfect continuous):

1. By 9 o'clock, we **had finished** our homework.
2. By the end of the month I **had lived** in this town for ten years.
3. By the end of this week we **had been working** on the project for a month.
4. They **had left** the classroom by the end of the hour.
5. By July the fifth they **had been studying** English for 3 years.
6. She **had been sleeping** for 10 hours by 11 o'clock.
7. We **had gone** home by next week.
8. We **had been looking for** him for 40 days by next Saturday.
9. She **had returned** from the excursion by 6 o'clock.
10. They **had bought** the new house by October?
11. They **had been waiting** for the president for 5 hours.
12. The sun **had not risen** by 4 o'clock.
13. You **had done** the shopping by 3 o'clock?
14. By 2018 we **had lived** in Madrid for 20 years.

You can adjust the answers depending on specific contexts and nuances, but these should all fit well!