1 have

2 not

3 been

4 has

5 got

1 can't

2 must

3 can't

4 may

21 can

22 shouldn't

23 mustn't

24 can

25 used to

16 will

17 may

18 used to

19 will

20 must

11 must

12 may

13 won't

14 doesn't have to

15 used to

6 doesn't have to

7 can't

8 will

9 won't

10 mustn't

1 can

2 should

3 shouldn't

4 can

5 have to

12 My sister drinks less coffee than my brother does

13 I eat less chocolate than she does

14 There is more rice on the plate than there is in the bowl

10 There isn’t as much noise in the country as there is in the city

11 I have fewer storybooks than my sister does

12 I don’t have as many music CD’s as my friends do

7 The red car is more expensive than the black one

8 Trung is the tallest in the group

9 Is this the best refrigerator you have?