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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In the last 7 years, humanity has discovered 43 potentially habitable planets.
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Only about 2% of the world population has green eyes.
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There is a mass reservoir of water floating in space that is 100,000 times bigger than our sun and holds 140 trillion times more water than all of our oceans.
11
In 2011, archaeologists discovered the skeletal remains of a Roman couple who have been holding hands for 1,500 years.
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