Ppbv
abbr. parts per billion by volume 十亿分体积比
🗣️ 情景例句
Are you kidding?
在开玩笑吗?
Truth is honest, truth is sure; Truth is strong and must endure.
真理不会骗人，切实无假；真理的力量强大，永存不垮。
Have you ever been bitten by a dog?
被狗咬过吗，你？