Unit Definition (t'sun) The t'sun is a Chinese unit of distance equal to 0.1 ch'ih or about 1.41 inches (3.58 centimeters).
Unit Definition (megameter) The parsec (symbol pc) is a unit of length used in astronomy. It stands for "parallax of one arc second", and is approximately 19,131,554,073,600 (19 trillion) miles.
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