Trả lời:
1, The meeting won't be held tonight.
2, The semina can't be held in the hall.
3, The bill has to be paid by Bill before the second of the month.
4, We should be sent it immediately.
5, That old building must be repaired as soon as possible.
6, Must the cheque be signed by the manager?
7, The door of the room couldn't be opened this morning.
8, Pictures used to be drawn when I was a boy.
9, A new house can be bought next year by my father.
Giải thích thêm: Chuyển câu chủ động sang câu bị động
Active: S + V + O
⇒ Passive: S(O) + to be + P2 + O(S)
~HỌC TỐT~