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Author Question: Hanna, at rest in her spaceship which is moving past Earth at 0.800 c, observes a neutron at rest ... (Read 59 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.
Urine turns bright yellow if larger than normal amounts of certain substances are consumed; one of these substances is asparagus.
All adults should have their cholesterol levels checked once every 5 years. During 2009–2010, 69.4% of Americans age 20 and older reported having their cholesterol checked within the last five years.
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.
Cancer has been around as long as humankind, but only in the second half of the twentieth century did the number of cancer cases explode.