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Did you know?

The first-known contraceptive was crocodile dung, used in Egypt in 2000 BC. Condoms were also reportedly used, made of animal bladders or intestines.

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Although the Roman numeral for the number 4 has always been taught to have been "IV," according to historians, the ancient Romans probably used "IIII" most of the time. This is partially backed up by the fact that early grandfather clocks displayed IIII for the number 4 instead of IV. Early clockmakers apparently thought that the IIII balanced out the VIII (used for the number 8) on the clock face and that it just looked better.

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Essential fatty acids have been shown to be effective against ulcers, asthma, dental cavities, and skin disorders such as acne.

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Sperm cells are so tiny that 400 to 500 million (400,000,000–500,000,000) of them fit onto 1 tsp.

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Amoebae are the simplest type of protozoans, and are characterized by a feeding and dividing trophozoite stage that moves by temporary extensions called pseudopodia or false feet.

Tracheostomy. A tracheotomy, or incision into the trachea, is performed to create an opening into th Tracheostomy. A tracheotomy, or incision into the trachea, is performed to create an opening into th
Eighteen-year-olds were the largest age cohort in the first year of the war in both armies. Soldiers Eighteen-year-olds were the largest age cohort in the first year of the war in both armies. Soldiers
Three days after the Boston Marathon explosion, the FBI released this photograph that had been taken Three days after the Boston Marathon explosion, the FBI released this photograph that had been taken
Vincent van Gogh, Letter to John Peter Russell. Vincent van Gogh, Letter to John Peter Russell.
Inline fuel filters are usually attached to the fuel line with screw clamps or threaded ... Inline fuel filters are usually attached to the fuel line with screw clamps or threaded ...
A lesion called a plaque in the brain of an individual with Alzheimer disease. A ring of degeneratin A lesion called a plaque in the brain of an individual with Alzheimer disease. A ring of degeneratin
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