句型转换。 1. My sister does housework every day.(变为否定句) My sister ______ ______ housework every day. 2. Is his name Jack? (作肯定回答) Yes, ______ ______. 3. They are American cars.(改为单数) ______ ______ ______ ______. 4. The girl under the tree is my sister. (对划线部分提问) ______ ______ is______ sister? 5. There is only one box in the room. (对划线部分提问) ______ ______ ______ ______ there in the room ? 6. There are some new watches in the bag. (对划线部分提问) ______ ______ in the bag ? 7. He usually goes home by bus. (同意句) He usually ______ ______ ______home.