gradation of test

例句：

1. 3.
   地质
2. 1. The company has implemented a new gradation system to improve efficiency.
   该公司已实施新的分级系统以提高效率。
3. 2.The scientist conducted a gradation study to understand the effects of pollution on ecosystems.
   科学家进行了一项分级研究，以了解污染对生态系统的影响。
4. 3.The gradation of colors in the painting is mesmerizing.
   这幅画中颜色的渐变令人着迷。