second order filter

例句：

1. 1. The engineer used a second-order filter to improve the accuracy of his measurements.
   工程师使用了一个二级过滤器来提高他测量的准确性。
2. 2. The company implemented a second-order filter to reduce its carbon footprint.
   公司实施了一个二级过滤器以减少其碳足迹。
3. 3.The scientist developed a second-order filter that could detect and remove pollutants from the air.
   科学家开发了一种二级过滤器，可以检测并从空气中去除污染物。