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Approximately 500,000 babies are born each year in the United States to teenage mothers.
Human kidneys will clean about 1 million gallons of blood in an average lifetime.
Blood in the urine can be a sign of a kidney stone, glomerulonephritis, or other kidney problems.
This year, an estimated 1.4 million Americans will have a new or recurrent heart attack.
There are 60,000 miles of blood vessels in every adult human.
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