:divide your school rules into 2 groups. first say what you must do at school. then say what you mustn"t do. example: we mast come to school on time. we mastn"t be late for school. !

At school you MUST DO : 1. Come on time; 2. Listen to the teacher at the lessons. ;
3. Be quiet at the lessons. 4.Do all your homework ; 5. Do what your teacher said to do. 
You MUSTN'T DO :  1. Be late. 2. Make some noise at the lessons. 3.Speak at the lessons. 4.Run in the hall. 5.Break school's things.

Надеюсь столько хватит.