Chuyển câu chủ động sang câu bị động

I knew that   they had told him of the metting. 
-> I knew
Nobody has ever treated me with such kindness.
-> I 
Do they teach English here?
-> Is
Did your teacher give you some exarvises?
-> Were 
Have they changed the window of the laboratory?
-> Has
Will the busses bring the children home?
->