(speak)
You mustn't speak.
(smoke)
You mustn't smoke.
(uniforms)
They/We/You must wear uniforms.
(listen)
You mustn't listen to music in class.
(turn on)
You must turn on your camera.
(at the weekend)
You don't have to wake/get up early at the weekend.
(cheat in exams)
You mustn't cheat in exams.
(eat)
You must eat fruit and vegetables/healthy food.
(uniforms)
They/You don't have to wear uniforms.
(listen)
You must listen to this CD.
(use your phone)
You mustn't use your phone in the car.
(keep distance)
You must keep distance.
(study)
She doesn't have to study. / You don't have to study.
(homework)
She must do her homework.
(feed)
She must feed her dog.