aerial n.天线

　　例句：The picture is much clearer with the new aerial.

　　装上新天线后画面清晰多了。

　　nitrogen n.氮

　　例句：Air consists chiefly of nitrogen.

　　空气主要由氮气组成。

　　oxygen n.氧

　　例句：Trees release oxygen into the air.

　　树木向空气中释放氧气。

　　oxide n.氧化物

　　例句：How can you get rid of this oxide coating?

　　你们该怎样除去这些氧化皮?

　　hydrogen n. 氢

　　例句：Water is composed of the elements hydrogen and oxygen.

　　水是由氢元素和氧元素组成的。