a nonmetallic bivalent element that is normally a colorless odorless tasteless nonflammable diatomic gas; constitutes 21 percent of the atmosphere by volume; the most abundant element in the earth's crust
oxygen的用法和样例:
例句
用作名词 (n.)
Water contains hydrogen and oxygen. 水含有氢和氧。
Hydrogen and oxygen are gases. 氢和氧是气体。
Plants can absorb carbon dioxide and release oxygen. 植物可以吸收二氧化碳释放氧气。
Mars is too dry and poor in oxygen. 火星上面过于干燥,并且缺乏氧气。