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Author Question: An undercover police officer is assigned the job of once a night walking each of the 48 blocks of a ... (Read 84 times) |
Blood is approximately twice as thick as water because of the cells and other components found in it.
In the United States, an estimated 50 million unnecessary antibiotics are prescribed for viral respiratory infections.
If all the neurons in the human body were lined up, they would stretch more than 600 miles.
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.
Autoimmune diseases occur when the immune system destroys its own healthy tissues. When this occurs, white blood cells cannot distinguish between pathogens and normal cells.