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Author Question: A hospitalized, alcohol-dependent patient believes spiders are spinning entrapping webs in the room. ... (Read 87 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.
Vaccines cause herd immunity. If the majority of people in a community have been vaccinated against a disease, an unvaccinated person is less likely to get the disease since others are less likely to become sick from it and spread the disease.
Blood is approximately twice as thick as water because of the cells and other components found in it.
There are over 65,000 known species of protozoa. About 10,000 species are parasitic.
In the United States, there is a birth every 8 seconds, according to the U.S. Census Bureau's Population Clock.