|
Author Question: In some of the countries in Tropical Africa, very long channels with many layers of intermediaries ... (Read 27 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.
During the twentieth century, a variant of the metric system was used in Russia and France in which the base unit of mass was the tonne. Instead of kilograms, this system used millitonnes (mt).
More than nineteen million Americans carry the factor V gene that causes blood clots, pulmonary embolism, and heart disease.
Alzheimer's disease affects only about 10% of people older than 65 years of age. Most forms of decreased mental function and dementia are caused by disuse (letting the mind get lazy).
The average human gut is home to perhaps 500 to 1,000 different species of bacteria.