Rewrite the sentences using must,mustn't, need to,has to,don't have to
2It isn't necessary for children to buy a ticket
Children..............................
3It's our duty to look after our health
We........................................
4It's necessary for Assel to do her exercises
Assel....................................
5It's against the rules to play football here
We........................................

Children don't have to buy a ticket.We must look after our health.Assel has to do her exercises.We mustn't play football here.