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Author Question: Periodic inspection of viewboxes, cassettes, and intensifying screens and tests to evaluate safe ... (Read 31 times) |
In 1864, the first barbiturate (barbituric acid) was synthesized.
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.
Pope Sylvester II tried to introduce Arabic numbers into Europe between the years 999 and 1003, but their use did not catch on for a few more centuries, and Roman numerals continued to be the primary number system.
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.
In the United States, an estimated 50 million unnecessary antibiotics are prescribed for viral respiratory infections.