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Asthma cases in Americans are about 75% higher today than they were in 1980.
There are 20 feet of blood vessels in each square inch of human skin.
Long-term mental and physical effects from substance abuse include: paranoia, psychosis, immune deficiencies, and organ damage.
The familiar sounds of your heart are made by the heart's valves as they open and close.
Asthma is the most common chronic childhood disease in the world. Most children who develop asthma have symptoms before they are 5 years old.
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