Complete the sentences with can, can`t, have to or don`t have to. In tennis you ... touch the net with your hand or racket.

In tennis you can\'t touch the net with your hand or racket. In tennis you can hold the racket with your left hand. In football, goalkeepers can\'t run all time. In horse-riding, you have to wear a riding hat. In underwater hockey, you don\'t have to wear flippers but they help you to swim quickly.