The Dallas/Ft. Worth airport is larger than New York City's Manhattan Island.
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The longest cave in the world is the 'Mammoth Cave System' in the USA at 560,000 mtrs deep!
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Every person in the world can fit in Texas and be given over 1000 sq ft in which to live.
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The Niagara Falls moves upstream at an average rate of about 295ft a century!
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The Amazon rainforest produces more than 20% the world's oxygen supply.
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More than a dozen men have stood on the surface of the moon, but only three have been to Challenger Deep in the Marianas Trench, the deepest known spot in the ocean.
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Due to gravitational effects, you weigh slightly less when the moon is directly overhead.
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