surface of discontinuity

例句：

1. 1. The surface of the lake is still and calm.
   湖的表面仍然平静。
2. 2.The scientist studied the surface of the earth to understand its geology.
   科学家研究地球的表面以了解其地质学。
3. 3. The new product has a smooth surface that makes it easy to clean.
   新产品有一个光滑的表面，这使得清洁变得容易。