XII. Complete the following sentences:

1. By the end of October ...
2. I decided to start working after ...
3. The bell had rung before ...
4. I met my school-mate after ...
5. By the time you finish translating the article ...
6. By the end of this decade ...
7. We shall not start discussing the problem if ...
8. Before she leaves for work ...
9. He won’t be able to do this work unless ...