1. Our teacher is a person whọ I really respect.
=> whom
2. Once upon a time there was a prince who was turned into a frog. x
3. I've lost the toys which you gave me.
=> that
4. He never appreciates his wife who has devoted all her life to him.
=> the
5. She keeps telling me things which I have already known.
=> what
6. This is the dog which I love very much.
=> what
7. I can't forget the lady họ offered me the job.
=> whom
8. Hue is the place which attracts many tourists. x