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There are more bacteria in your mouth than there are people in the world.
When blood is exposed to air, it clots. Heparin allows the blood to come in direct contact with air without clotting.
The immune system needs 9.5 hours of sleep in total darkness to recharge completely.
Pubic lice (crabs) are usually spread through sexual contact. You cannot catch them by using a public toilet.
In the United States, an estimated 50 million unnecessary antibiotics are prescribed for viral respiratory infections.
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