1. You should||must watch this film. It's very good.
2. We must||should wear uniforms at our school.
3. You mustn't||shouldn't take dogs into the park. It isn't allowed.
4. You shouldn't||mustn't buy that T-shirt. It's expensive.
5. You should||must wear a hat. It's very sunny.
6. You mustn't||shouldn't pick flowers here. That's the rule.