16. I have
been playing
17. I will
have been working
18. will
have delivered
19. have
been practicing
20.had done
1. had been
learning
2 . is
repairing/has been doing
3. will
have been reading
4. have you
been sitting/have you been writing/have been waiting
5.works/will
have been working
6. has been
walking /hasn`t come
7. have
been saving/ will have had
8. have you
known/ have known
9. had been
experimenting
10. is
snowing/has been snowing
11.studies/will
have been studying
12. were
you doing/was preparing/had been preparing