Preoxidation
预氧化
🗣️ 情景例句
My vacation was terrible, it rained the whole time.
我的假期简直糟透了，整天都在下雨。
I've been part of this project since its beginning.
从一开始我就参与这个计划。
In the letter he was asked to call at the station.
要他到警察局去一趟。