Lurch, a Watusi bull, had the largest horns in the world.
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Only about 2% of the world population has green eyes.
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Mars had an oxygen-rich atmosphere around 4 billion years ago
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The focusing muscles of the eyes move around 100,000 times a day. To give your leg muscles the same workout, you would need to walk 80km (50 miles) every day.
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Your body is creating and killing about 2.4 million red blood cells per second.
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