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Autoimmune diseases occur when the immune system destroys its own healthy tissues. When this occurs, white blood cells cannot distinguish between pathogens and normal cells.

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Pubic lice (crabs) are usually spread through sexual contact. You cannot catch them by using a public toilet.

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Human stomach acid is strong enough to dissolve small pieces of metal such as razor blades or staples.

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The human body's pharmacokinetics are quite varied. Our hair holds onto drugs longer than our urine, blood, or saliva. For example, alcohol can be detected in the hair for up to 90 days after it was consumed. The same is true for marijuana, cocaine, ecstasy, heroin, methamphetamine, and nicotine.

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About 3% of all pregnant women will give birth to twins, which is an increase in rate of nearly 60% since the early 1980s.

Old people Old people
In the 1800s, most people were poor, and formal education beyond the first several grades was a ... In the 1800s, most people were poor, and formal education beyond the first several grades was a ...
A propaganda poster enshrining Stalin proclaims that he has led his people “Forward to ... A propaganda poster enshrining Stalin proclaims that he has led his people “Forward to ...
Older people who experienced stressful events in their younger years may show personal growth and ... Older people who experienced stressful events in their younger years may show personal growth and ...
Demographic change and the effect on people social, and economic life Demographic change and the effect on people social, and economic life
People in poor, urban areas often find themselves in “food deserts" People in poor, urban areas often find themselves in “food deserts"
Video: Proteins Defined, Hierarchy & Composition of Cells

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