Ppb
[化] 十亿分率
🗣️ 情景例句
I'd miss them a lot,
我会非常想念他们的，
Don't cross the bridge till you get to it.
不要杞人忧天。
I told her what the revolutionaries were doing and I persuaded her to help me.
我告诉她革命者都在干些什么事，并说服她给我帮忙。