Ppm.
[医] 兆比率(百万分之几)
🗣️ 情景例句
I know what you mean. I'v been there.
我明白你的意思。 我深有体会。
Who is speaking?I don't recognize your voice.
阁下是那一位？我听不出你的声音。
In Miss Gao's class there are forty-six students.
在高老师的班上有四十六个学生。