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Pubic lice (crabs) are usually spread through sexual contact. You cannot catch them by using a public toilet.
Bacteria have been found alive in a lake buried one half mile under ice in Antarctica.
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.
More than 50% of American adults have oral herpes, which is commonly known as "cold sores" or "fever blisters." The herpes virus can be active on the skin surface without showing any signs or causing any symptoms.
More than 2,500 barbiturates have been synthesized. At the height of their popularity, about 50 were marketed for human use.