The oldest stone tools found are dated from 2.7 - 2.9 million years ago. The species that made these tools is unknown.
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On average, there's 100 billion neurons in the human brain.
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The adult human brain weighs about 3 pounds (1,300-1,400 g).
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It has been scientifically proven that stroking a cat can lower one's blood pressure!
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It takes about 20 seconds for a red blood cell to circle the whole body.
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If the human eye was a digital camera, it would have 576 megapixels.
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There are about 255 babies born worldwide every minute.
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