11. They are going to build a bridge in the area.
A bridge in the area is going to be built.
→ bị động của TLG: S + is/am/are + going to + be + $V_{3}$ (+ by O)
12. They clean the streets everywhere.
The streets are cleaned everywhere.
→ bị động của HTĐ: S + is/am/are + $V_{3}$ (+ by O)
13. The manager must sign the cheque.
The cheque must be signed by the manager.
→ bị động của modal verbs: S + modal verbs + be + $V_{3}$ (+ by O)
14. They have postponed the concert.
The concert has been postponed.
→ bị động của HTHT: S + has/have + been + $V_{3}$ (+ by O)
15. They have built a new hospital near the airport.
A new hospital near the airport has been built.
→ bị động của HTHT: S + has/have + been + $V_{3}$ (+ by O)