Here are the best answers for the questions provided:

5. Don't bother me while I **am doing** the exercise. (B)
6. I think the weather **will** be bad tomorrow. (B)
7. We **were** there when our father died. (A)
8. I **am** in the room right now. (D)
9. **When** did she work for this bank? (C)
10. Her sister **never read** a book until she was ten. (B)
11. If you **want** to be a doctor, you have to study harder. (A)
12. I’ll come and see you before I **leave** for the States. (A)
13. It was very kind of you to **show** the way. (A)
14. Most people are into **traveling** to different parts of the world. (A)
15. Linda was not at the office the day **before** yesterday. (D)

If you have any further questions or need clarification, feel free to ask!