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The horizontal fraction bar was introduced by the Arabs.
In most climates, 8 to 10 glasses of water per day is recommended for adults. The best indicator for adequate fluid intake is frequent, clear urination.
A cataract is a clouding of the eyes' natural lens. As we age, some clouding of the lens may occur. The first sign of a cataract is usually blurry vision. Although glasses and other visual aids may at first help a person with cataracts, surgery may become inevitable. Cataract surgery is very successful in restoring vision, and it is the most frequently performed surgery in the United States.
In 2012, nearly 24 milliion Americans, aged 12 and older, had abused an illicit drug, according to the National Institute on Drug Abuse (NIDA).
Asthma occurs in one in 11 children and in one in 12 adults. African Americans and Latinos have a higher risk for developing asthma than other groups.