拱点

例句：

1. 1. The bridge hasan arched roof that spans theriver.
   这座桥有一个拱形的屋顶，横跨河流。
2. 2. The arches of thebridge are made of stone and support theweight of the road.
   这座桥的拱门是用石头做的，支撑着道路的重量。
3. 3. The arches of the bridge weredesigned to provide a safe passage for pedestrians.
   这座桥的拱门被设计成为行人提供一个安全的通行通道。