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Author Question: A teacher assists a young boy in writing the letters of the alphabet by holding his hand and guiding ... (Read 124 times) |
The horizontal fraction bar was introduced by the Arabs.
Anti-aging claims should not ever be believed. There is no supplement, medication, or any other substance that has been proven to slow or stop the aging process.
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.
Nitroglycerin is used to alleviate various heart-related conditions, and it is also the chief component of dynamite (but mixed in a solid clay base to stabilize it).
Most childhood vaccines are 90–99% effective in preventing disease. Side effects are rarely serious.