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If all the neurons in the human body were lined up, they would stretch more than 600 miles.
Earwax has antimicrobial properties that reduce the viability of bacteria and fungus in the human ear.
There are over 65,000 known species of protozoa. About 10,000 species are parasitic.
Blood is approximately twice as thick as water because of the cells and other components found in it.
There are 60,000 miles of blood vessels in every adult human.
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