ce
mobile phones at school.)
Read the poster. Choose the correct word in each sentence. Write in your
notebook.
1. You mustn't/don't have to bring food and drink into the lab.
2. You mustn't/must ask a teacher before you print anything.
3. You don't have to/mustn't tell others your password.
4. You have to/mustn't turn off your computer when you leave.
5. You must/don't have to leave the lab before 5 pm.
should / shouldn't​