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Egg cells are about the size of a grain of sand. They are formed inside of a female's ovaries before she is even born.
Blood in the urine can be a sign of a kidney stone, glomerulonephritis, or other kidney problems.
You should not take more than 1,000 mg of vitamin E per day. Doses above this amount increase the risk of bleeding problems that can lead to a stroke.
Vaccines prevent between 2.5 and 4 million deaths every year.
The average adult has about 21 square feet of skin.
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