catenarian arch

例句：

1. 1. The catenarian arch is a unique feature of the tree's trunk.
   双足纲动物的拱形门是这棵树树干的独特特征。
2. 2.The discovery of this arch has sparked debate about its significance in the ecosystem.
   这一拱形门的发现引发了对它在生态系统中重要性的辩论。
3. 3. The arch was built by ancient artisans to mark the path of the river.
   这个拱是由古代工匠建造的，用来标记河流的路径。