Show up and explain to them that you've missed your flight, and ask if you can fly standby for another flight. Where are you flying to? Look up the schedules and have some flight numbers handy. You might have to go to the principal's office for being tardy though. Your parents won't like that.
Are you serious, or pulling our leg? If you are, then my apologies for the sarcasm.
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preez mine da pratform gahp.