4 ms·
further illustrated here in Chinese: http://www.wikiwand.com/zh-mo/%E7%AE%97%E8%A1%A8_%28%E6%B8%85%E5%8D%8E%E7%AE%80%29 http://www.wikiwand.com/zh-mo/%E7%AE%97
by jerryhuang100 11y ago
further illustrated here in Chinese:
http://www.wikiwand.com/zh-mo/%E7%AE%97%E8%A1%A8_%28%E6%B8%85%E5%8D%8E%E7%AE%80%29 http://www.wikiwand.com/zh-mo/%E7%AE%97%E8%A1%A8_%28%E6%B8%8...