A good moisturizer works two ways: first, it contains ingredients known as emollients (like petrolatum) that coat the skin and provide a barrier to moisture loss.

• 一种好的保湿乳液在两方面起效：首先，它包含有润肤剂的成分（像矿脂），这为皮肤披上了一层外衣并且提供了一个屏障来锁住水分。