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When blood is exposed to air, it clots. Heparin allows the blood to come in direct contact with air without clotting.
Bacteria have been found alive in a lake buried one half mile under ice in Antarctica.
Everyone has one nostril that is larger than the other.
Human stomach acid is strong enough to dissolve small pieces of metal such as razor blades or staples.
Today, nearly 8 out of 10 pregnant women living with HIV (about 1.1 million), receive antiretrovirals.
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