=>
22. The tables had been cleaned by Joe.
23. The key had been lost by us.
24. A fight had been started.
25. An article had been being read by me.
26. The window had not been closed.
27. The paper had not been bought.
28. I had not been noticed by her.
29. Had the problem been solved by her?
30. Had that song been recorded by him?
Bị động thì QKHT
(+) S had been V3/ed (by O)
(-) S had not been V3/ed (by O)
(?) Had S been V3/ed (by O)?
Bị động thì QKHTTD : S had been being V3/ed (By O)