A secret art However, for several thousand years, fangzhongshu has not only not been widely known in China, it has been treated as knowledge to be hoarded and sold at a high price.
奇貨可居，秘傳之術然而數千年來，房中術在中國非但不普及，反倒是以一種「奇貨可居」的方式在交易買賣。