ppb

📖毕业后词汇十亿分之一百万分之一十亿分之二

ppb 的定义

  1. paper, printing, and binding.
  2. parts per billion.

更多ppb例句

  1. So long as detected levels of carbendazim are low enough, in the range of 10 to 35 ppb, they can stay for sale.