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The familiar sounds of your heart are made by the heart's valves as they open and close.

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The most dangerous mercury compound, dimethyl mercury, is so toxic that even a few microliters spilled on the skin can cause death. Mercury has been shown to accumulate in higher amounts in the following types of fish than other types: swordfish, shark, mackerel, tilefish, crab, and tuna.

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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.

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There used to be a metric calendar, as well as metric clocks. The metric calendar, or "French Republican Calendar" divided the year into 12 months, but each month was divided into three 10-day weeks. Each day had 10 decimal hours. Each hour had 100 decimal minutes. Due to lack of popularity, the metric clocks and calendars were ended in 1795, three years after they had been first marketed.

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Hippocrates noted that blood separates into four differently colored liquids when removed from the body and examined: a pure red liquid mixed with white liquid material with a yellow-colored froth at the top and a black substance that settles underneath; he named these the four humors (for blood, phlegm, yellow bile, and black bile).

Bipolar disease. The term bipolar means “pertaining to two poles.” The individual with this form of Bipolar disease. The term bipolar means “pertaining to two poles.” The individual with this form of
Modern primate study sometimes involves high-tech methods. This golden lion tamarin is having a batt Modern primate study sometimes involves high-tech methods. This golden lion tamarin is having a batt
Shy children often have a high arousal level in novel social situations. Over time, parents can help ... Shy children often have a high arousal level in novel social situations. Over time, parents can help ...
Children with attention deficit disorder with hyperactivity (ADHD) diagnoses typically need a quiet, ... Children with attention deficit disorder with hyperactivity (ADHD) diagnoses typically need a quiet, ...
The posted octane rating in most high-altitude areas shows regular at 85 instead of the usual 87. The posted octane rating in most high-altitude areas shows regular at 85 instead of the usual 87.
Permafrost: High albedo, reflects as much as 90% of the Sun’s energy Permafrost: High albedo, reflects as much as 90% of the Sun’s energy
Video: Acids and bases - definition

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