1. The old house has just been sold.
Bị động thì HTHT: S+has/have+been+V3/ed.

2. The cake was so hard that I couldn't eat it.
It+be+such+a/an++adj+N+that+clause->N+be+so+adj+that+clause.

3. It is 10 years since I last heard this song.
S+last+V2/ed+O+time -> It is+time+since+S+last+V2/ed+O.

4. It took 2 hours to fly from HN to HCM city.
two-hour flight = take 2 hours to fly

5. If we had enough money, we could buy that house.
Không thể xảy ra ở hiện tại -> Câu điều kiện loại 2.

câu bị động ta có cấu trúc : 

 s + be + v3 + by + O 

1 The old house has just been sold by them.

2 The cake was so hard that I couldn't eat it.

3 It is ten years since I last heard this song -> câu HTHT sau since + QKĐ

4 It took two hours to fly from Ha Noi to Ho Chi Minh City.

5 If we had enough money, we could buy that house. -> câu ĐK loại 22