水沖 不 走,火燒不掉, 60 水沖不走 火燒不掉 吃了 不 飽,人人需要。 吃了不飽 人人需要 猜 一 種自然元素 猜一種自然元素 Guess what? Water can’t move it. Fire can’t burn it. Eat it and you are not full, But everyone needs it. ( A natural element ) 71