Must:
feed the dog, change your shoes, be on time, do your homework, speak loudly in the library, take your medicine, study for your exams.
Mustn't:
smoke, eat too much sugar, drink cold water, drop letter, use your mobile in class, cheat in tests, stay in bed.
Must:
feed the dog, change your shoes, be on time, do your homework, speak loudly in the library, take your medicine, study for your exams.
Mustn't:
smoke, eat too much sugar, drink cold water, drop letter, use your mobile in class, cheat in tests, stay in bed.