Ppb
[化] 十亿分率
🗣️ 情景例句
OK. Let's see.
好 ，让我们看看。
Many a good cow hath a bad calf.
虎父生犬子。
Both Maori and Pacifice Islanders are encouraged to use their own languages.
政府鼓励毛利人与太平洋岛民使用他们自己的语言。