s called sweet potato. Because it comes from a foreign land, it is also called sweet potato. One mu (a unit of area) yields dozens of stones, which is twenty times more than rice. It can be eaten fres...轉碼失敗!請您使用右上換源切換源站閱讀或者直接前往源網站進行閱讀!er from the Qinhuai River tastes like rouge. I imagine that our current emperor, if he could still open his eyes and see this scene today, would surely be grateful to the wise man who advised him back...