should, shouldn't; have to, don't have to

You .......... keep the bus you ride clean. 

• have to

• don't have to

• should

• shouldn't

You ........... be selfish. You .......... give your seat to the elderly people.

• shouldn't / shouldn't

• shouldn't / should

• don't have to / shouldn't

• don't have to / should

I ........... show my ID card at the check-in counter. If not, I won't get the boarding pass.

• have to

• don't have to

• should

• shouldn't

Sandra ............. pay for train ticket every time. I have enough money to pay for myself.

• shouldn't

• should

• doesn't have to

• has to

We ............ print our e-ticket at home. We can do it at the train station.

• should

• shouldn't

• don't have to

• have to

People ............. be patient waiting in-line for their turn at the ticket vending machine. 

• have to

• shouldn't

• don't have to

• should

All passengers ............ report any animal or plant they have with them at the Plant and Animal Quarrantine counter.

• have to

• has to

• don't have to

• doesn't have to

Sandra ............. top up her electronic money every day.

• have to

• has to

• doesn't have to

• don't have to