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Did you know?

Astigmatism is the most common vision problem. It may accompany nearsightedness or farsightedness. It is usually caused by an irregularly shaped cornea, but sometimes it is the result of an irregularly shaped lens. Either type can be corrected by eyeglasses, contact lenses, or refractive surgery.

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In 1844, Charles Goodyear obtained the first patent for a rubber condom.

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The modern decimal position system was the invention of the Hindus (around 800 AD), involving the placing of numerals to indicate their value (units, tens, hundreds, and so on).

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Acute bronchitis is an inflammation of the breathing tubes (bronchi), which causes increased mucus production and other changes. It is usually caused by bacteria or viruses, can be serious in people who have pulmonary or cardiac diseases, and can lead to pneumonia.

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The top five reasons that children stay home from school are as follows: colds, stomach flu (gastroenteritis), ear infection (otitis media), pink eye (conjunctivitis), and sore throat.

During World War I, advancing armies unloosed ferocious artillery barrages to destroy deeply entrenc During World War I, advancing armies unloosed ferocious artillery barrages to destroy deeply entrenc
A roller cell-type electric fuel pump. A roller cell-type electric fuel pump.
A severe case of delayed contact dermatitis (Type IV hypersensitivity) from wearing latex gloves. A severe case of delayed contact dermatitis (Type IV hypersensitivity) from wearing latex gloves.
Cycads, a Type of Gymnosperm Cycads, a Type of Gymnosperm
Each allele of codominant genes is fully expressed in heterozygotes. Type A blood has A antigens on Each allele of codominant genes is fully expressed in heterozygotes. Type A blood has A antigens on
Video: Chronology of leptin research (A history of leptin research)

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