Complete the sentences with 'must', 'have to', 'need to', 'don't have to', or 'don’t need to'. 

1. Airline rules say that passengers ______________ be at the gate 15 minutes before departure.

2. We _____________ book the tour. It's not a busy time.

3. Passengers _______________ seated during take off and landing.

4. If we don't want to pay extra, we ______________ leave the hotel before the check-out time.

5. I ______________ pack my bag tonight. I leave tomorrow.

6. You _____________ make reservations for the train. You can buy the ticket on the day you travel.