Ppbv
abbr. parts per billion by volume 十亿分体积比
🗣️ 情景例句
I'm through with you!
我们之间完了。
I ask him to do the washing now.
我要求他现在做洗涤工作。
In this way Native Americans were forced onto poor land that the settlers did not want.
就这样，美洲土著人被赶到殖民者所不要的贫瘠的土地上去了。