16 is - taking

17 is studying

18 is singing

19 is writing

20 is talking

11 isn't walkng

12 is speaking

13 is - doing - is watching

14 are watching

15 is sitting

6 works

7 do not see

8 goes

9 aren't

10 does-play

1 Does - buy

2 Do - visit

3 is - doesn't work

4 do - do

5 visit - stay

11 will conme

12 was walking - was sleeping

13 had buzzed - answered

14 was watching

15 will look

6 had finished - invited

7 went - had finished

8 was ironing

9 died

10 told

1 joined - was

2 lost - has been

3 was

4 won't go - will stay

5 had ended - got

1 Not only do some people think that camping is cheaper, but they actually also prefer it to hotels

2 Not only is he good at English, but he also draws very well

3 Not only does he sing well, but he also plays musical instruments perfectly

4 Not anything at all did they do

Nothing at all did they do

3 C

4 D

5 B

6 D

7 A

8 D

9 D

10 D

11 B

12 A

21 A

22 A

23 A

24 C

25 A

26 C

27 A

28 D

29 A

30 A

31 C