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Did you know?
The horizontal fraction bar was introduced by the Arabs.
Did you know?
In the United States, an estimated 50 million unnecessary antibiotics are prescribed for viral respiratory infections.
Did you know?
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.
Did you know?
Adult head lice are gray, about ? inch long, and often have a tiny dot on their backs. A female can lay between 50 and 150 eggs within the several weeks that she is alive. They feed on human blood.
Did you know?
In 1844, Charles Goodyear obtained the first patent for a rubber condom.