CLASS RULES
obligation & prohibition
Must
-You must study.
-You must raise your hand.
-You must sit properly. 
You must copy the
vocabulary in your
notebook.
Mustn't
-You mustn't chew
crim in classroom.
-You mustn't eat or
drink in classroom.
-You mustn't open your
partner's lockers.
-You mustn't open visit
facebook in class.
