Ppmv
abbr. parts per million by volume 百万分体积比
🗣️ 情景例句
After Richard was born.
等生下Richard之后。
There's no such thing as a free lunch.
天下没有白吃的午餐。
It is eight o'clock.The children go to school by car every day, but today, they are going to school on foot.
现在是8点钟。孩子们每天都乘小汽车去上学，而今天，他们正步行上学。