氢是由氢元素和氧元素组成的。
Water is composed of the elements hydrogen and oxygen.

氢分子含有两个氢原子和一个氧原子。
A molecule of water consists of two atoms of hydrogen and one atom of oxygen.

氢由氢和氧化合而成。
Water is composed of hydrogen and oxygen.

氢和氧是气体。
Hydrogen and oxygen are gases.

氢含有氢和氧。
Water contains hydrogen and oxygen.

氢极易爆炸。
Hydrogen is highly explosive.

氢个氢原子和一个氧原子结合而成一个水分子。
Two atoms of hydrogen combine with one atom of oxygen to form a molecule of water.

氢由氢和氧组成。
Water is composed of hydrogen and oxygen.