1. Sources of energy will be used more effectively for our future. (Câu bị động thì TLĐ: S+will be+P.P) 

2. I used to stay up late to watch football matches last year, but now I don't. (Used to:đã từng| S+used to +V_inf) 

4. Why don't you go to work by bike? (Why don't+O+V) 

5. There is less clean water than the past. (So sánh hơn-kém) 

8. The light will be turned of when leaving the room or going to bed. (Câu bị động thì TLĐ) 

9. Minh used to my best friend. (Giống câu 2) 

10. These walls won't be painted tomorrow. (Câu bị động dạng phủ định thì TLĐ: S+won't be+P.P) 

11. Giống câu 2

12. People used to travel to work by bicycle but now they don't. 

13. There used to be some trees in the field, but now there aren't any. 

1, Sources of energy will be used more effectively for our future.
2, I used to stay up late to watch football matches last year.
4 ,why don't we go to work by bike?
5, There is less clean water than in the past.
8, The lights will be turned off when leaving a room or going to bed.
9, Minh used to be my best friend.
10, These walls will not be painted tommorow.
12, People used to travel to work by bicycles some years ago.
13, There used to be some trees in the field.

Xin hay nhất ạ