Ex. 1
1) don’t have to
2) have to
3) have to
4) don’t have to
5) does she have to take the dog for a walk every day?
Ex. 2
Peter has to wear a uniform.
Peter doesn’t have to work in an office.
Peter has to carry a big bag.
Peter doesn’t have to work on Sundays.
Peter has to work on Saturdays.
Peter doesn’t have to use a computer.
Ex. 3
1) a
2) b
3) a
4) a
5) b
Ex. 4
1) mustn’t
2) have to
3) have to
4) have to
5) have to