pulpal

例句：

1. 1.The tree's pulpal is rotting away.
   这棵树的树干正在腐烂。
2. 2.The roots of the tree are visible through the soil.
   树根在土壤中可见。
3. 3. The pulpal of the tree is where the sap flows from.
   树的树干是树液流动的地方。