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Adult head lice are gray, about ? inch long, and often have a tiny dot on their backs. A female can lay between 50 and 150 eggs within the several weeks that she is alive. They feed on human blood.
After a vasectomy, it takes about 12 ejaculations to clear out sperm that were already beyond the blocked area.
Multiple sclerosis is a condition wherein the body's nervous system is weakened by an autoimmune reaction that attacks the myelin sheaths of neurons.
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).
More than nineteen million Americans carry the factor V gene that causes blood clots, pulmonary embolism, and heart disease.
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