Say why you must/mustn't

1) wear a seat belt: You must wear a seat belt for your safety while driving or sitting in a car. 2) look both ways when you cross the road: You must look both ways to ensure there are no vehicles approaching and it is safe to cross. 3) walk on the pavement: You must walk on the pavement to stay safe from traffic on the road. 4) talk to the driver: You mustn't talk to the driver as it can distract them and cause accidents. 5) run onto the road: You mustn't run onto the road to avoid accidents. 6) lean out of the window: You mustn't lean out of the window to prevent injuries.