Ex.1 Zakreśl właściwą odpowiedź.

a) You must/mustn’t run in the corridor at school.
b) You must/mustn’t follow the school rules.
c) You must/mustn’t use your mobile in class.
d) You must/mustn’t return your library books on time.
e) You must/mustn’t drop litter.
f) You must/mustn’t study for your exams.
g) You must/mustn’t change your shoes.
h) You must/mustn’t cheat in tests.