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Author Question: Approximately __________ of the people in the U.S. are upper middle class. a. 10 percent b. 15 ... (Read 80 times) |
Giardia is one of the most common intestinal parasites worldwide, and infects up to 20% of the world population, mostly in poorer countries with inadequate sanitation. Infections are most common in children, though chronic Giardia is more common in adults.
The average office desk has 400 times more bacteria on it than a toilet.
Approximately 500,000 babies are born each year in the United States to teenage mothers.
Vampire bats have a natural anticoagulant in their saliva that permits continuous bleeding after they painlessly open a wound with their incisors. This capillary blood does not cause any significant blood loss to their victims.
It is believed that humans initially contracted crabs from gorillas about 3 million years ago from either sleeping in gorilla nests or eating the apes.