There are about 1,400 different species of bacteria in your belly button.
10
The human brain doesn't stop developing until about 25 years old.
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The adult human brain weighs about 3 pounds (1,300-1,400 g).
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Blue eyes are a genetic mutation. Before the mutation occured, all humans had brown eyes.
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A person can live without food for about a month, but only about a week without water.
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Coughing can cause air to move through your windpipe faster than the speed of sound - over a thousand feet per second!
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