Ppbv
abbr. parts per billion by volume 十亿分体积比
🗣️ 情景例句
I'd like to check this book out.
我想借这本书。
I left the house at 8 o'clock and got to work at 8:30.
我在8点钟离开了房子并且在8:30上班了。
He has never borrowed money from me.
他从未向我借过钱。