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Blood is approximately twice as thick as water because of the cells and other components found in it.
Malaria was not eliminated in the United States until 1951. The term eliminated means that no new cases arise in a country for 3 years.
Egg cells are about the size of a grain of sand. They are formed inside of a female's ovaries before she is even born.
Blood in the urine can be a sign of a kidney stone, glomerulonephritis, or other kidney problems.
There are more bacteria in your mouth than there are people in the world.
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