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Choose the most appropriate modal verb. There are situations where both verbs are possible. Can you say why?

1. Passengers mustn’t / don’t have to smoke anywhere on the aircraft.

2. All personnel should / must wear their badge while in the building?

3. The visitors don’t have to / mustn’t enter the radioactive zone unless authorised.

4. I think you should / must learn how to negotiate in Chinese. It would be a good skill if you had the time to learn it!

5. My boss doesn’t have to / shouldn’t travel so much - he is looking ill!

6. When going to a new country to do business , you should / must do some research on the etiquette and taboos of the host country.

7. Monday is a public holiday. I mustn’t / don’t have to work.