Ppm.
[医] 兆比率(百万分之几)
🗣️ 情景例句
I can't figure out why he quit his job.
我不能理解他为什么要辞职。
By little and little the wolf eateth the sheep.
狼吃羊，一只一只进肚肠。
What?Speak up. Penny.I'm afraid I can't hear you.
什么？彭妮，大声一点。我可听不见你念的。