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Did you know?
Vaccines prevent between 2.5 and 4 million deaths every year.
Did you know?
The horizontal fraction bar was introduced by the Arabs.
Did you know?
All adults should have their cholesterol levels checked once every 5 years. During 2009–2010, 69.4% of Americans age 20 and older reported having their cholesterol checked within the last five years.
Did you know?
Your skin wrinkles if you stay in the bathtub a long time because the outermost layer of skin (which consists of dead keratin) swells when it absorbs water. It is tightly attached to the skin below it, so it compensates for the increased area by wrinkling. This happens to the hands and feet because they have the thickest layer of dead keratin cells.
Did you know?
In 1844, Charles Goodyear obtained the first patent for a rubber condom.