There's m,any theories as to what the seven rooms symbolize but here are two popular ones. The rooms symbolize the seven stages of life from birth to death or that the rooms symbolize the seven levels of Hell. Take your pick, you can probably argue better for the first one, though. Each color has significance to the stage of life it represents, I can't remember all the different colors, but you get the idea.
I think the answer would be replace, i'm taking a test with Penn Foster with the same question
I would say it is a good book review. You described what happened in detail and I was able to picture the events of the book. However, I would change your answer for the theme. A theme is the moral of a story. For example: "Don't judge a book by its cover," or "All actions have consequences." So find a theme that best fits the story and you'll be good.
