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Home Q & A Board Humanities History
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fx-82 fx-82
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9 years ago
China was susceptible to frequent earthquakes, so a seismograph invented under the Han Dynasty used which of these mechanisms?
a.   a suspended weight moves a lever which drops balls into a frog’s mouth
b.   a magnetic arm moves a writing instrument across a piece of parchment
c.   specially colored wooden dragons float in a vat of colored water
d.   two chemicals are separated inside an urn; when shaken they produce a distinct glow
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6eculus6eculus
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9 years ago
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fx-82 Author
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#2
9 years ago
Very nice, thanks!
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#3
9 years ago
This was a tough question, glad it was right.
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