Ppbv
abbr. parts per billion by volume 十亿分体积比
🗣️ 情景例句
And twist, twist.
扭摆 扭摆。
Women commonly live longer that men.
女性通常比男性长寿。
Ships may be delayed by storms; flights may be cancelled because of bad weather, but trains must be on time.
轮船船期可能因风暴而推延，飞机航班可能因恶劣天气而取消，唯有火车必然是准点的。