"一个水分子是由两个氢原子和一个氧原子组成"...用英语怎样说 (机译免进)

给你看牛津高阶英汉双解的molecule这个单词解释的例句：
A molecule of water consists of two atoms of hydrogen and one atom of oxygen.
完整词条如下：
molecule
/ ˈmɔlɪkjuːl; ˋmɑləˏkjul/ n smallest unit (usu consisting of a group of atoms) into which a substance can be divided without a change in its chemical nature 分子:A molecule of water consists of two atoms of hydrogen and one atom of oxygen.水分子含有两个氢原子和一个氧原子.

以下提供北美译法：
One water molecule contains two hydrogen and one oxygen atoms.