Part5. choose the best answer

1. visit/go

2. has learnt

3. have

4. knew

5. was built

6. are delivered

7. into

8. natural

9. the red leaf

10. interseted

11. harmful

Part 4.

1. Effects( ảnh hưởng)

2. Up

3. Plant( thực vật)

4. Used

5. Efective( hiệu quả)

Part 6.

1. Went

2. Are planted( câu bị động)

3. Is served

Part 7. 

1. Many activities have been cancalled because of the covid19 epdemic

2. If we try to protect our best the environment, it will be clean

3. Tom’s parents are very sad because he studies very badly every semester 

Part 8.

1. After David had gone home, we arrived.

2. tea can't be made with cold water

3. when did you learn english?

4. unless people through rubbish in the street, the street is clean