n.忧郁
A cloud is a condensation of water vapour. 云是由水蒸汽凝缩而成的。
A cloud is a mass of vapour in the sky. 云是天空中的水汽团。
Water can be changed into vapour when heated. 水被加热时，可以变成水蒸汽。
His brain was clouded by vapours and dreams. 他的脑子里充满空想和梦幻。
It can change water into vapour. 它能把水变成蒸汽。
The sun exhales vapours from the sea. 阳光使海水蒸发。
