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
