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Nearly 31 million adults in America have a total cholesterol level that is more than 240 mg per dL.
If you could remove all of your skin, it would weigh up to 5 pounds.
Human kidneys will clean about 1 million gallons of blood in an average lifetime.
There are over 65,000 known species of protozoa. About 10,000 species are parasitic.
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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