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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Scientists at the Zhejiang University in China have developed an ultra-light material known as carbon aerogel.
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In 2011, archaeologists discovered the skeletal remains of a Roman couple who have been holding hands for 1,500 years.
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You forget 90% of your dreams.
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Only about 2% of the world population has green eyes.
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