Present Perfect / Past Simple. Use either the Present Perfect or Past Simple in the following sentences. 
A) Past Simple B) Present Perfect

14. I’m not sure we ____ (to meet) before.
15. You ____ (to be, always) my closest friend.
16. When you _____ (to go) to Brazil? 
17. It’s two months since I _____ (to start) diving me car. 
18. This is the first time I ______ (to eat) so many hamburgers.
19. My father ______ (to work) for that company for 5 years. Than he gave it up.
20. I ______ (to use) to be afraid of dogs. 
21. Susan ______ (to use) to sit in her room and play the piano for hours.