1. 云是由水蒸汽凝縮而成的。
   A cloud is a condensation of water vapour.
2. 水受熱變成水蒸汽。
   Heat evaporates water into steam.
3. 水加熱則成為蒸汽，冷卻則成為冰。
   Water is changed into steam by heat and into ice by cold.
4. 他用蒸汽把信封上的郵票揭下來。
   He steamed the stamp off the envelope.
5. 蒸汽冷卻時凝結(jié)成水。
   Steam condenses into water when cooling down.
6. 蒸汽機車已被柴油內(nèi)燃機車所取代。
   The steam locomotives were superseded by diesel units.
7. 這些發(fā)動機是由蒸汽驅(qū)動的。
   The engines are driven by steam.
8. 水被加熱時，可以變成水蒸汽。
   Water can be changed into vapor when heated.

蒸的英語翻譯：

汽的英語翻譯：