Please help me with this PASSIVE VOICE STRUCTURE
1. people said that he was a good doctor. (the original sentence)
=> It was said that he was a good doctor/ he was said to be a good doctor (my two passive sentences- are they correct?)
2. they thought he had been one of famous singers.(the original sentence)
=> It was thought he had been one of famous singers./ He was thought to have been one of famous singers.(my two passive sentences- are they correct?)
3. Opening the door, we saw her overhearing us.(the original sentence)
=> Opening the door, she was seen overhearing us(my passive sentence- is it correct?)