Chuyển từ câu chủ động sang câu bị động ;
1) The statue broke while they were moving it to another room in the museum .
2)After he had told a story , we clapped our hands .
3) They had taken the victim to hospital before the police came .
4) Had they pulled down the building to make way for a new road before you came back ?
5) She had not informed me of the date of the meeting before another classmate of mine told me about it .
6) Someone had invented electric lights before I was born .