15. D

S + Vbe + Adj + to_V

16. C

17. A

invetion (n): phát minh

18. A

diễn tả 1 hành động ở hiện tại ta dùng HTĐ

19. B 

S1 + asked + O + S2 + if/wheter + V(lùi thì): câu tường thuật dạng câu hỏi Yes/No

20. C

Vbe + Adj - ở đây ta k chọn A vì careless nghĩa là bất cẩn

IV.

21. Great Wall is located in China.

22. It is 1,500 miles long.

23. It was built from 246 to 209 BC.

24. The purpose of the Great Wall is keep out their enemies.

25. It is made of brick and earth.

Bạn học tốt ~

# _quynhly_

15.D

16.C

17.A

18.A

19.B

20.C

21. Great Wall located in China

22. There is a wall that is 1,500 miles long 

23. It was built from 246 to 209 BC

24. The people of China made is to keep out their enemies

25. It is made of brick and earth