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The horizontal fraction bar was introduced by the Arabs.

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About one in five American adults and teenagers have had a genital herpes infection—and most of them don't know it. People with genital herpes have at least twice the risk of becoming infected with HIV if exposed to it than those people who do not have genital herpes.

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In most cases, kidneys can recover from almost complete loss of function, such as in acute kidney (renal) failure.

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Pregnant women usually experience a heightened sense of smell beginning late in the first trimester. Some experts call this the body's way of protecting a pregnant woman from foods that are unsafe for the fetus.

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Hip fractures are the most serious consequences of osteoporosis. The incidence of hip fractures increases with each decade among patients in their 60s to patients in their 90s for both women and men of all populations. Men and women older than 80 years of age show the highest incidence of hip fractures.

African bush (savanna) elephant in Etosha National Park, Namibia. African bush (savanna) elephant in Etosha National Park, Namibia.
Specimen in the Doñana National Park Specimen in the Doñana National Park
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The “Big Four” world leaders meet at the Hotel Crillon in Paris, 1919. From left to right (front row The “Big Four” world leaders meet at the Hotel Crillon in Paris, 1919. From left to right (front row
John Muir (right) with President Roosevelt at Yosemite National Park John Muir (right) with President Roosevelt at Yosemite National Park
Video: Smoking Cessation

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