After so much rich food, on the 13th day you should have simple rice congee and mustard greens (choi sum) to cleanse the system.

吃了那么多大餐之后，十三那天，人们就和稀粥吃芥菜清肠胃。

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Cadmium is frequently found in leafy vegetables such as spinach and choi sum grown in polluted conditions.

WSJ: Cadmium-Tainted Rice Found in Guangzhou