Помогите пожалуйста с английским, нужно вставить правильное время, и пожалуйста напишите объяснение, почему вставлено именно это время
Use the correct form of the verb (Active Voice, all tenses).
1. He (to become) a manager when he was 25.
2. Our distributor called while I (to talk) to Jim.
3. How long (to work) in sales?
4. Our employees (to be) our strongest asset.
5. Our office usually (to close) at 5 PM, but today we’re staying open until 6.
6. By the time my boss gets here, I (to finish) my report.
7. I (not to be) to a trade fair until I went to the one in Las Vegas last month.
8. They were one of our biggest competitors, but they (to go) bankrupt last year.
9. The company (to develop) into one of the biggest electronics retailers in the country.
10. The recent survey shows that our consumer base (to grow).
11. Last month the board (not to approve) the merger.
12. I (to work) at Bank of America from 2001-2003.
13. Currently, I (to work) at Citibank.
14. You (to finish) preparing the presentation by the time I get back from lunch?
15. How many different jobs he (to apply) for?
16. I (to start) my new job next week.
17. They (to buy) 10,000 shares next week.
18. We currently (to negotiate) that part of the contract.