1 C

2 A

3 A

4 C

5 B

b)

6 recycle plastic bags

7 plant more trees

8 clean the river up

9 run a marathon

10 raise money

1 let => let's 

2 plant => planting

3 joining => join

4 us buy => we buy

5 helping => help

6 How about we organize a car wash?

7 Let's take part in a talent show

8 We should organize a fair craft

9 How about donating old books for poor children?

10 I think we should raise money for planting trees

Lỗi ảnh r bạn ưi

1 I have never painted a mural over graffiti

2 Mr Binh has recycled rubbish for 2 years

3 Because David was lazy, he failed the exam

4 It's five months since they last cleaned up the street

5 We began donating books and clothes 10 years ago

1 If he doesn't smoke too much, he can get rid of his cough

2 If she isn't shy, she will enjoy the party

3 If I get a work permit, I will stay for another month

4 If he pays me tonight, I will have enough money to buy a car

5 If you are impatient, you will make mistakes

23 C

24 C

25 D

26 C

27 B

28 B

29 B

30 B

31 C

32 C

33 C

34 B

35 D

36 D

37 A