Ppbv
abbr. parts per billion by volume 十亿分体积比
🗣️ 情景例句
It's our anniversary; let's go somewhere special to celebrate.
今天是我们的结婚纪念日， 我们去一个特别的地方庆祝吧。
Air China has a flight leaving at 9:25.
中国航空公司有一班飞机，9点28分起飞。
An old woman is standing at the side of the road.
一位老大娘站在靠近红绿灯的路边。