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Author Question: Derek, a Web designer, works for a pharmaceutical company. He uploads information about the ... (Read 20 times) |
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.
The average human gut is home to perhaps 500 to 1,000 different species of bacteria.
Not getting enough sleep can greatly weaken the immune system. Lack of sleep makes you more likely to catch a cold, or more difficult to fight off an infection.
There are more nerve cells in one human brain than there are stars in the Milky Way.
In the ancient and medieval periods, dysentery killed about ? of all babies before they reach 12 months of age. The disease was transferred through contaminated drinking water, because there was no way to adequately dispose of sewage, which contaminated the water.