We know that every kind of there are when the outside pressure is greater than the saturation vapor pressure of the substance, the substance of the steam began into liquid droplets.

• 我们知道，每一种物质都存在饱和蒸汽压，当外界压强大于该物质的饱和蒸汽压时，这种物质的蒸汽就开始凝结成液滴。