Ppbv
abbr. parts per billion by volume 十亿分体积比
🗣️ 情景例句
OK. We'll ring you up at 6:00 a.m. tomorrow.
嗯，我们会在明天6点整叫您。
I'm busy!
我在忙啦！
It is quite possible that the thief might put some meat in you bag.
这个窃贼很可能把肉放到你的袋子里。