请找出下列各句中的错误并加以改正。 1. This is the factory where we visited last week. __________________________________________________________________ 2. This is the watch for which Tom is looking. __________________________________________________________________ 3. The person to who you spoke is a student of Grade Two. __________________________________________________________________ 4. The house in that we live is very small. __________________________________________________________________ 5. The sun gives off light and warmth, that makes it possible for plants to grow. __________________________________________________________________ 6. I've read all the books which I borrowed from the library. __________________________________________________________________ 7. This is the best film which I have ever seen. __________________________________________________________________ 8. My father and Mr Smith talked about things and persons who they remembered in the country. __________________________________________________________________ 9. Everything which we saw was of great interest. __________________________________________________________________ 10. His dog, that was now very old, became ill and died. __________________________________________________________________