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Author Question: What happens to water as it is heated? a. It becomes heavier. b. It becomes lighter. c. The ... (Read 53 times) |
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.
The Centers for Disease Control and Prevention (CDC) was originally known as the Communicable Disease Center, which was formed to fight malaria. It was originally headquartered in Atlanta, Georgia, since the Southern states faced the worst threat from malaria.
In 1844, Charles Goodyear obtained the first patent for a rubber condom.
Most childhood vaccines are 90–99% effective in preventing disease. Side effects are rarely serious.
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.