There are over 65,000 known species of protozoa. About 10,000 species are parasitic.
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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).
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The U.S. Preventive Services Task Force recommends that all women age 65 years of age or older should be screened with bone densitometry.
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Medication errors are more common among seriously ill patients than with those with minor conditions.
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Excessive alcohol use costs the country approximately $235 billion every year.
Mercury (element)
Regional Organizations
How to find the average atomic mass of an element
A Human Element Emerges
The five skills of the element Collection of Information