Ppm.
[医] 兆比率(百万分之几)
🗣️ 情景例句
They don't ask how much someone paid for something.
他们不问别人买某个东西要花多少钱。
Evil comes to us by ells and goes away by inches.
罪恶来时，尺进寸退。
Is it your brother?
是你弟弟？