subterraneous stem的用法和樣例：
例句
- The stem is reduced to a disklike structure, bearing concentric layers of fleshy leaf bases that comprise the food store.
由許多肥厚的肉質(zhì)鱗葉包圍扁平或圓盤(pán)狀的地下莖，其中儲藏著(zhù)大量的營(yíng)養物質(zhì)。 - A potato consists mainly of starch stored by the potato plant in its underground stem.
馬鈴薯的主要成份是淀粉，是由馬鈴薯身把它存在其地下莖里的。
