Ppm.
[医] 兆比率(百万分之几)
🗣️ 情景例句
His books exposed people to new ideas.
他的书使人们接触了新思潮。
Cindy's sister will arrive in eight days.
辛迪的姐姐八天后将到。
I wish I had followed your advice.
我真希望我采纳了你的建议。