gradation for surface pollution

例句：

1. 3.
   地质
2. 1. The company's growth has been a gradation of successes and failures.
   公司的增长是一系列成功和失败的累积。
3. 2. The gradation of the light through the leaves was mesmerizing.
   透过树叶的光的渐变令人着迷。
4. 3. The gradation of colors in the painting is breathtaking.
   这幅画中颜色的渐变令人叹为观止。