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.
14
The city of Houston, Texas is built on a swamp and is slowly sinking!
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There are more than 50,000 earthquakes throughout the world every year!
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Every year, Alaska has about 5,000 earthquakes.
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The Amazon rainforest produces more than 20% the world's oxygen supply.
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It takes a drop of ocean water more than 1,000 years to circulate around the world.
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