Ответ:

1) had (a)

2) will watch (a)

3) does(a)

4) will not go(c)

5) helped(b)

6) likes(a)

7) thanked( a)

8) jumped(a)

9)cleans(b)

10)will skate(b)

11)washed (a)

12) played (a)

13)skied(a)

14) helped(a)

15) went(c)

16) will.cook(c)

17) didn't go (a)

18)shall read (c)

19)will(a)

20)I will visit(a)

21)saw(a)