betsey: hurry up, Rob. we mustn't be late!
mark: don't worry, mum. he's got two hours.
betsey: but he must be at the airport two hours before his flight.
mark: no, you needn't. rob's bag is not very heavy. we must go straight to the check-in desk.
rob: there are a lot of them. which one is for rob's flight?
betsey: look at the information board. what is the flight number?
rob: it's British Airways, flight 345.
betsey: fine, so we must go then to desk 112.
rob: what must we do there?
betsey: we m