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The immune system needs 9.5 hours of sleep in total darkness to recharge completely.
There are more bacteria in your mouth than there are people in the world.
Today, nearly 8 out of 10 pregnant women living with HIV (about 1.1 million), receive antiretrovirals.
Human kidneys will clean about 1 million gallons of blood in an average lifetime.
There are more sensory neurons in the tongue than in any other part of the body.
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