Ppm.
[医] 兆比率(百万分之几)
🗣️ 情景例句
Your photo in it helped, too.
在报纸上的照片也有帮助。
Counsel must be followed, not praised.
忠告必须照办，而不是赞美。
One of the most famous sailing ships of the nineteenth century, the Cutty Sark, can still be seen at Greewich.
人们在格林威治仍可看到19世纪最有名的帆船之一“卡蒂萨克”号。