4 ms·
http://en.wikipedia.org/wiki/List_of_Chinese_discoveries http://en.wikipedia.org/wiki/List_of_Chinese_discoveries Scroll down and look for Circadian rhythm.
by j-kidd 14y ago
http://en.wikipedia.org/wiki/List_of_Chinese_discoveries http://en.wikipedia.org/wiki/List_of_Chinese_discoveries
Scroll down and look for Circadian rhythm.