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Author Question: A strong negative correlation between the frequency of cigarette smoking and the frequency of mate ... (Read 11 times) |
A cataract is a clouding of the eyes' natural lens. As we age, some clouding of the lens may occur. The first sign of a cataract is usually blurry vision. Although glasses and other visual aids may at first help a person with cataracts, surgery may become inevitable. Cataract surgery is very successful in restoring vision, and it is the most frequently performed surgery in the United States.
Drying your hands with a paper towel will reduce the bacterial count on your hands by 45–60%.
Bacteria have flourished on the earth for over three billion years. They were the first life forms on the planet.
Intradermal injections are somewhat difficult to correctly administer because the skin layers are so thin that it is easy to accidentally punch through to the deeper subcutaneous layer.
Most childhood vaccines are 90–99% effective in preventing disease. Side effects are rarely serious.