chuyển sang câu bị động passive voice
30/nobody showed them their seats.
31/they have sold that old houses at the end of the road.
32/their teachers are making them learn hard this semester.
33/he couldn't repair the broken vase.
34/people say that he is a robber.
30. Nobody was shown them their seats.
31. They have been sold that old houses at the end of the road.
32. Their teachers are being made them learn hard this semester.
33. He could not be repaired the broken vase.
34. People are said that he is a robber.