Đáp án là

7. All of us can complete this exercise easily because it's not difficult.

8. They asked where we are going to spend our holiday.

9. Would you mind sending me details of the courses and fees.

10. Would you mind opening the door?

11.Would you mind if I opened the door?

12. The refrigerator should be kept closed to save electricity.

13. Nam asked Hung what kinds of clothes he liked best.

14. Hoa invited Nga to go out for dinner with them.

15.I used to go fishing with my friends when I was a small boy.

16. It has been two weeks ago since the last time Peter wrote to his parents.

Peter hasn't written to his parents for two years.

17. Unless she hurries, she will be late for school.

18. My car is going to be repaired tomorrow.

I am going to have my car repairs tomorrow.

19. They told me not to live in this area because it very dangerous.

20. If Hoa got up early, she would be late for school.

21. If you are patient, you will be successful.