Rewrite the class rules using 'must' or 'mustn't'.

{ "q": "Rewrite the class rules using 'must' or 'mustn't'.", "a": "1. Students must not use their smartphones in class. 2. Students must do their homework on time. 3. Students must not chew gum at school. 4. Students must respect the teachers and other students. 5. Students must stand up when the teacher enters the classroom. 6. Students must not cheat in exams. 7. Students must not run in the school corridors. 8. Students must be quiet in the library."}