`11.` Tea can't be made with cold water.

`->` Bị động với ĐTKT: can + be + Vpp.

`12.` The police weren't informed that there had been a mistake.

`->` Bọ động QKĐ: was/were Vpp.

`13.` When are the results of the contest going to be announced?

`->` Bị động TLG: am/is/are going to be Vpp.

`14.` Look! The seals are being fed.

`->` Bị động HTTD: am/is/are being Vpp.

`15.` Is that airplane being flown by a pilot student?

`->` Bị động HTTD: am/is/are being Vpp.

11. Tea can't be made with cold water.

→ câu bị động dạng động từ khiếm khuyết: S + can/could/should/would/must ... (not) + be + V3/ed + (by+O)

12. The police wasn't informed that there had been a mistake.

→ câu bị động thì QKĐ: S + was/were + V3/ed + (by+O)

13. When are the results of the contest going to be announced?

→ câu bị động thì TLG: S + is/am/are + going to + be + V3/ed + (by+O)

14. Look!The seals are being fed.

→ câu bị động thì HTTD: S + is/am/are + being + V3/ed + (by+O)

15. Is that airplane being flown by a pilot student?

→ câu bị động thì HTTD