noun ダウンロード 🔗共有 辺材 Sapwood; the soft, newer wood in the trunk of a tree found between the bark and the hardened heartwood. Examples : "The tree's alburnum was a pale yellow color, easily distinguished from the darker heartwood. " その木の辺材は薄い黄色で、より濃い心材とは容易に区別できた。 plant material nature biology structure AIとチャット語彙ゲーム読解練習