oxygen是什么
问题描述：
oxygen是什么
答
oxygen['ɔksidʒən]
n.氧, 氧气
例句:
Water contains hydrogen and oxygen.
水含有氢和氧.
Oxygen masks are used in aircraft only in emergencies.
飞机上的氧气面具只用於紧急情况.
Hydrogen and oxygen are gases.
氢和氧是气体.