ページの作成:「<br> The bark of white oak isn't white. The cambium is found between the bark and the sapwood of a tree. Because the cambium hardens, it leaves a ring on the timber, [ht…」
(ページの作成:「<br> The bark of white oak isn't white. The cambium is found between the bark and the sapwood of a tree. Because the cambium hardens, it leaves a ring on the timber, [ht…」)