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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).
The Babylonians wrote numbers in a system that used 60 as the base value rather than the number 10. They did not have a symbol for "zero."
Methicillin-resistant Staphylococcus aureus or MRSA was discovered in 1961 in the United Kingdom. It if often referred to as a superbug. MRSA infections cause more deaths in the United States every year than AIDS.
Cytomegalovirus affects nearly the same amount of newborns every year as Down syndrome.
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.