III/

1. Have offered

2. Cleaned

3. Have you ever recycled

4. Tutors

5. Did you provide

6. Has donated

7. Has Tom participated

8. Didn't start

9. Do your friends sing

10. Haven't finished

IV/

1. We haven't completed cleaning up the streets yet because they are very dirty.

2. The children do not have enough warm clothes because their families are very poor.

3. We talk and sing for the elderly people because it makes them happy.

4. We provide evening classes for street children because they do not have opportunity to go to school.

5. You should recycle rubbish because it helps protect the environment.

Chúc bạn học tốt.

III,

1. have offered

2. cleaned

3. Have you ever recycled...?(thêm have ở đầu câu nha bn)

4. tutors

5. Did you provide...?(thêm did ở phía trc nhé bn)

6. will donate

7. Has Tom participated....?(thêm has ở phía trc câu nhé bn)

8. didn't start

9. Do your friends sing...?(thêm do ở phía đầu câu nha bn)

10. haven't finished

IV,

1=>C

2=>D

3=>E

4=>A

5=>B