Răspuns:
1 Students mustn't run in the corridors.
2 You mustn't drop litter on the pavement.
3 We don't have to take an umbrella.It's sunny today.
4 She don't have to walk to school.Mum is taking her by car.
5 Cyclists mustn't forget their helmets.
6 He don't have to pay the entrace to the museum, it's free.