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Author Question: Scientists are observing a rapid decrease in polar ice owing to global warming. How might a warming ... (Read 199 times) |
Signs of depression include feeling sad most of the time for 2 weeks or longer; loss of interest in things normally enjoyed; lack of energy; sleep and appetite disturbances; weight changes; feelings of hopelessness, helplessness, or worthlessness; an inability to make decisions; and thoughts of death and suicide.
There are 20 feet of blood vessels in each square inch of human skin.
When blood is exposed to air, it clots. Heparin allows the blood to come in direct contact with air without clotting.
Most childhood vaccines are 90–99% effective in preventing disease. Side effects are rarely serious.
About one in five American adults and teenagers have had a genital herpes infection—and most of them don't know it. People with genital herpes have at least twice the risk of becoming infected with HIV if exposed to it than those people who do not have genital herpes.