〔R34〕  A pitcher with a thousand chinks.

                 Yet never lets out the water it drinks.

〔譯註〕 一個水罐帶著千個裂罅，卻從不放出它所喝的水。

〔提問〕 If it is a porous (多孔的) substance (物質), what is it?

〔謎底〕 s_____