Ppbv
abbr. parts per billion by volume 十亿分体积比
🗣️ 情景例句
I look forward to seeing you and Harry and Michelle.
我等着见 Harry和Michelle。
I wish you to be more careful.
我希望你更谨慎。
Another time, possibly, but not Friday.
换个时间还有可能，但不要在星期五。