常見例句A cloud is a condensation of water vapour. 云是由水蒸汽凝縮而成的。A cloud is a mass of vapour in the sky. 云是天空中的水汽團(tuán)。Water can be changed into vapour when heated. 水被加熱時(shí),可以變成水蒸汽。relative vapour density 相對蒸氣密度vapour density apparatus 蒸汽密度器 返回 vapour density