桶形穹窿

例句：

1. 1. The mountain was shaped like a barrel, creating a unique natural formation.
   这座山的形状像桶一样，形成了独特的自然景观。
2. 2. The architect designed the building with a barrel-shaped dome, adding an artistic touch to the structure.
   建筑师设计了一座带有桶形穹顶的建筑，给建筑增添了艺术气息。
3. 3. The barrel-shaped cavern provided shelter for the animals during the harsh winter months.
   这个桶形洞穴在恶劣的冬季为动物提供了庇护所。