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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.
A good example of polar molecules can be understood when trying to make a cake. If water and oil are required, they will not mix together. If you put them into a measuring cup, the oil will rise to the top while the water remains on the bottom.
Cancer has been around as long as humankind, but only in the second half of the twentieth century did the number of cancer cases explode.
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.
Allergies play a major part in the health of children. The most prevalent childhood allergies are milk, egg, soy, wheat, peanuts, tree nuts, and seafood.
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