concave region

例句：

1. 1. The concaveregion of the mountain is home to avariety of wildlife.
   这座山的凹面区域是各种野生动物的家园。
2. 2. Theconcave region of the lake is perfectfor kayaking.
   湖的凹面区域非常适合划独木舟。
3. 3. Theconcave region ofthe earth's crust iswhere tectonic plates converge.
   地球地壳的凹面区域是板块碰撞的地方。