We ... work together with the class.
must
We ... interrupt other students.
mustn't
We ... listen to the teacher.
must
We ... behave well.
must
We ... mustn't bully other students.
mustn't
We ... take part in project work.
must
We ... put the hand up to speak.
must
We ...come to classes on time.
must
We ... fail the test.
mustn't
We ... be noisy.
mustn't
We ... come late for classes.
mustn't