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ANS: DPrinting was invented in China in the ninth century.
ANS: AThe clock anticipated the economic analaysis of Adam Smith, as the increase in the wealth of nations comes from improvement in the productivity of labor.
Human kidneys will clean about 1 million gallons of blood in an average lifetime.
Egg cells are about the size of a grain of sand. They are formed inside of a female's ovaries before she is even born.
More than 34,000 trademarked medication names and more than 10,000 generic medication names are in use in the United States.
The Romans did not use numerals to indicate fractions but instead used words to indicate parts of a whole.
In 1864, the first barbiturate (barbituric acid) was synthesized.
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