2 sentences

1. 每个分子由两个氢原子和一个氧原子组成。

   měi gè fēn​zǐ yóu liǎng gè qīng​yuán​zǐ hé yī gè yǎng yuán​zǐ zǔ​chéng.

   Each molecule is composed of two hydrogen atoms and one oxygen atom.

   Source: Dong Chinese Dictionary

2. 每个水分子由两个氢原子和一个氧原子组成。

   měi gè shuǐ fēn​zǐ yóu liǎng gè qīng​yuán​zǐ hé yī gè yǎng yuán​zǐ zǔ​chéng.

   Each water molecule is composed of two hydrogen atoms and one oxygen atom.

   Source: Dong Chinese Dictionary