решить раскрыть скобочки ​

Тип а что со скобками делать, как, по какому правилу?

9. Has been staying

10.have you met

11. did he use to live in

12. did you do

13. had arrived, knew, had taken

14. will go, will you go

15. I am having

16. had doubled

17. have to be

18. had to, had to

19. saw

20. will be able