xylem core

例句：

1. 1.The tree's xylem core is the main part of its structure that supports the leaves and branches.
   这棵树的木质部核心是它的主要结构部分，支撑着叶子和树枝。
2. 2. The xylem core plays a crucial role in the transportation of water and nutrients throughout the plant.
   木质部核心在植物体内水分和养分的运输过程中起着至关重要的作用。
3. 3.In some species, the xylem core can be used as a source of food for insects or other organisms.
   在某些物种中，木质部核心可以作为昆虫或其他生物的食物来源。