Ppm.
[医] 兆比率(百万分之几)
🗣️ 情景例句
Forgive me if I'm wrong, but haven't we met before.
如果我弄错的话请原谅我，我们以前见过面吧？
One false move may lose the game.
一著不慎，满盘皆输。
When several elephants are being trained at one time,
几只象同时训练时，