We .......................... drop the litter on the ground.
mustn't
We ........................... listen to music in the classroom.
mustn't
We ............................ put litter in the bins.
must
We .............. be polite and help people.
must
We ................................ be naughty or laugh at people.
mustn't
We ....................... wash our hands before lunch.
must
We .................. be hardworking and listen to the teachers.
must
We ....................... do our homework.
must
We ......................... shout in class.
mustn't
We ................ be quiet in the library.
must
We ............................... use mobile phones at school.
mustn't
We ...................... eat and drink in the classroom.
mustn't