1. The speech was delivered by Mr. Tuan yesterday

2. The computer is turned off at night

3. The floor is cleaned by me every day

4. This dress was bought by my mother this morning

5. This exercise was done by her two days ago

6. He is sent abroad to study chemistry

7. This room hasn't been used for a long time

8. My bike has been stolen 

9. A letter from his parents has just been received

10. This house will be bought by her

11. My house is being built by them

12. At this time yesterday, my new dress was being made by Lan

1.The speech was delivered  yesterday
2.The computer should be turned off at night
3.The floor is cleaned  everyday
4.This dress was bought  this morning
5.This exercise was done two days ago
6.He is sent abroad to study chemistry
7.This room has been used for a long time
8.My bike has been stolen
9.A letter has been just received from his parents 
10.This house will be bought 
11.My house is being built 
12.My new dress was being made at this time yesterday