- A cloud is a condensation of water vapour.
云是由水蒸汽凝缩而成的。
- This water vapour rises, condenses on cooling, and falls as rain.
水蒸汽升入空中,遇冷凝成雨滴而下降。
- A cloud is a mass of vapour in the sky.
云是天空中的水汽团。
- If it were not for the vapour in the air, there would be no dew.
如果空气中没有水汽,就没有露水。