Write positive and negative sentences, using "must/mustn't".

1. Drivers must drive on the right-hand side of the road.

2. You mustn't drive after you drink alcohol.

3. Small children mustn't sit in the front seat of the car.

4. Vehicles must have seats for small children.

5. Drivers and passengers of motorcycles must wear helmets.

6. You mustn't drive at more than 50 km/h on this road.

7. You mustn't use a mobile phone when you are driving.