Complete the sentences using the correct form of have to/has to, don't have to/doesn't have to, can/can't.
1) it isn't possible to drive a car when you're only twelve years old.
you.
2) my mother is a teacher. it's very important for her to be ready for every class.
my mother.
3) we don't have mathematics tomorrow. it's not necessary to do the homework tonight.
we.
4) it isn't necessary for Asyl to pay in trolleybus because he's got a plass ticket.
Asyl.
