Write what you must / mustn39;t do or be at schoolpolite

1. We must be polite with our classmates and teachers at school.
2. We must listen to the teacher at school.
3. We mustt be late for school.
4. We must be friendly with each other and with our guests at school.
5. We mustnt miss lessons at school.
6. We must come to school on time.
7. We mustnt use mobile phones at school during lessons.