Odpowiedź:
1. The referee has to have a whistle.
2. Players mustn't kick their opponents.
3. We don't have to wear football boots for PE.
4. X: Do you have to play hockey at your school?
Y: No, we don't.
5. X: Do cyclists have to wear helmets?
Y: Yes, they do.
6. What do players have to do in this game?
