平底河谷

例句：

1. 1.The valley is home to many rare species of plants and animals.
   这个山谷是许多稀有植物和动物的家园。
2. 2. The river flows through the valley, creating a picturesque landscape.
   这条河流流经山谷，创造出一幅如画的风景。
3. 3. The valley is surrounded by mountains, providing a natural barrier for wildlife.
   山谷被山脉环绕，为野生动物提供了自然的屏障。