21/ had met

22/ wonder-are waiting

23/ is playing

24/ do you get-go-go

25/ don't you put- will go - Will you come

26/ haven't been

27/ have read

28/ Were-having

29/ weren't

30/ doesn't rain

31/ was sitting

32/ will visit

33/ stops

34/ comes

35/ ride

36/ didn't speak.

$Ex12.$

1/ They have learnt English for 10 years.

2/ The last time she wrote to her friends was 2 years ago.

3/ I haven't played tennis since June.

4/ It's a long time since I last came back to my hometown.

5/ We haven't met her since last year.

6/ This is the first time we have eaten meat.

7/ When did you start driving a car?

8/ I haven't met my friends since we left school.

9/ We have lived her for 15 years.

10/ She hasn't visited me for 5 months.

11/ I haven't written to my uncle since July.

12/ We have become close friends for a long time.

13/ Minh has collected stamps since 2000.

14/ I haven't seen Minh for 5 months.

.....