Ppmv
abbr. parts per million by volume 百万分体积比
🗣️ 情景例句
Small world. I'm from Titusville, too.
世界真小。我也是从Titusville来的。
Maybe we could start with the Designing Department.
也许我们可以先参观一下设计部门。
who rolled balls down inclined planes,
他就是那个使球体沿斜面向下滚动，