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In 1835 it was discovered that a disease of silkworms known as muscardine could be transferred from one silkworm to another, and was caused by a fungus.
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).
Cancer has been around as long as humankind, but only in the second half of the twentieth century did the number of cancer cases explode.
In 2012, nearly 24 milliion Americans, aged 12 and older, had abused an illicit drug, according to the National Institute on Drug Abuse (NIDA).
Approximately 70% of expectant mothers report experiencing some symptoms of morning sickness during the first trimester of pregnancy.