molecule

n. 分子

We can see many molecules flying in the air when a sunbeam penetrated the dark room.

当一束光线穿进暗淡的房间时，我们可以看到空气中有许多小颗粒在飞舞。

Two atoms of hydrogen combine with one atom of oxygen to form a molecule of water.

两个氢原子和一个氧原子结合而成一个水分子。