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The horizontal fraction bar was introduced by the Arabs.
There are 20 feet of blood vessels in each square inch of human skin.
About 3% of all pregnant women will give birth to twins, which is an increase in rate of nearly 60% since the early 1980s.
Approximately 500,000 babies are born each year in the United States to teenage mothers.
Approximately 15–25% of recognized pregnancies end in miscarriage. However, many miscarriages often occur before a woman even knows she is pregnant.
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