Odpowiedź:
1. The referee has 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, I don't have to.
5. x: Do cyclist have to wear a helmet?
y: Yes, they have to.
6. What do players have to do in this game?
