根据短文内容，用括号内所给词的适当形式填空，使短文完整、通顺。
Susan is a great girl. At school she always follows the (rule). She always arrives at school on time. And she always (wear) her uniform to school. At school she never fights her classmates. In the classroom, in the dining hall or in the library she always keeps quiet. When the classroom, the dining hall and the library (be) dirty, she always helps to clean (they). Her teachers and classmates like her very much.