Ppbv
abbr. parts per billion by volume 十億分體積比
??? 情景例句
If you don't like it, I whis you would say so.
如果你不喜歡，我希望你能說(shuō)出來(lái)。
He's been behind bars for almost 30 years.
他坐了將近30年牢。
As a matter of fact, it is the other way around.
事實(shí)上，情況正好相反。