=>
1. The house is cleaned every day.
-> bị động HTĐ is/am/are V3/ed
3. I will be collected at the airport by John.
-> bị động TLĐ will be V3/ed
4. We are taught how to speak English properly by Mr. Robinson.
-> bị động HTĐ
5. This form must be signed by your teacher.
-> bị động must be V3/ed 
6. Football is played all over the world.
-> bị động HTĐ
7. A class discussion will be held by our form teacher next Monday.
-> bị động TLĐ
9. Jeans can't be worn at work.
-> bị động can't be V3/ed
11. The rice was separated from the husk.
-> bị động QKĐ was/were V3/ed
12. A fire was made by the boys' camp.
-> bị động QKĐ
13. This house was built more than one hundred years ago.
-> bị động QKĐ
14. Millions of tons of rice are exported by Vietnam every year.
-> bị động HTĐ
15. Vietnamese people's Lunar New Year is celebrated around January or February.
-> bị động HTĐ
16. Trees are usually planted in Vietnamese people's neighborhood after Tet holiday.
-> bị động HTĐ
19. The publisher's book was published in 1996.
-> bị động QKĐ 
20. Our desk was repaired during the weekend.
-> bị động QKĐ