Giúp mình với mọi người ơi !!!

=>
1. Had been -> were 
2. Unless -> if
3. Had knew -> had known 
4. Am -> were 
5. Find in -> find out
6. Had realized -> realized 
7. You would do -> would you do
8. Is not -> was
9. Had I known -> I had known 
10. Will go -> would go
11. Be -> been
12. Because -> if
13. Is -> were 
14. Will study -> study
15. Would to go -> would go 
16. To -> for
17. Occur -> would occur 
18. Would have studied -> had studied