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The immune system needs 9.5 hours of sleep in total darkness to recharge completely.
There are over 65,000 known species of protozoa. About 10,000 species are parasitic.
More than 34,000 trademarked medication names and more than 10,000 generic medication names are in use in the United States.
In most cases, kidneys can recover from almost complete loss of function, such as in acute kidney (renal) failure.
More than 2,500 barbiturates have been synthesized. At the height of their popularity, about 50 were marketed for human use.
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