3. My friend sent me a letter last week.

 ……I was sent a letter by my friend last week……

4. They will not build a hotel near my school.

 …A hotel will not be built near my school………

5. We collect paper for recycling.

 …Paper is collected for recycling……………

6. She doesn’t clean the classroom every day.

 ……The classroom isn't cleaned every day………

7. Lan does her housework in the morning.

 ……lan's housework is done in the morning………

8. Miss Thu has made me a new dress.

 ……I was made a new dress by Miss Thu….

9. Tim must clean the floor everyday.

 ……The floor must be cleaned by Tim everyday………...

10. My father can play the guitar. .

 …The guitar can be played by my father……...

11. You should eat more vegetables. .

 ……More vegetables should be eaten …...

12. Did you invite her to your house? .

 …was she invited to your house?………...

13. He usually reads 2 newspapers a day.

 …2 newspapers are usually read a day…

14. I have learned English for 5 years.

 ……English has been learned for 5 years…...

15. He speaks English well. .

 …………English is spoken well………...

16.Tom wrote this report yesterday.

 ……This report was written by Tom yesterday………..

17. We planted a lot of flowers in Da Lat.

 ……A lot of flowers were planted in Da lat………

18. They haven’t finished the test yet.

 ………The test hasn't been finished yet………..

19. Do they hold a meeting every month?

 ……Is a meeting held every month?….

20. People speak French and English in Canada?

 ……French and English are spoken in Canada……