You must ______ at the airport an hour before your plane leaves.

A．from second --hand information
B．gathered more from other sources than (from)its inhabitants
C．gained from the arguments about the country
D．different from what one had before the travel

A．will gradually disappear because of ease of travel
B．do exist even though different nationalities behave exactly alike
C．will always continue to exist and the world will be a dull place
D．will not exist as one hopes