【英语时差8,16】嘴唇为何会干？2

 What this means is that our lips have little to no protection from the environment, and their main source of moisture is the saliva¹ that comes from our mouths. What’s more, unlike much of the rest of our body, our lips are almost always on display, and rarely covered by clothing. As a result, the moisture on our lips is continually evaporating. And that’s before we take into account exposure to sun, wind, cold, and air-conditioning. Plus, if you’re sick or have allergies², and your nose is congested, your lips end up drying more quickly because you tend to breathe through your mouth.

1 saliva   

n.唾液，口水

参考例句：

• He wiped a dribble of saliva from his chin.他擦掉了下巴上的几滴口水。
• Saliva dribbled from the baby's mouth.唾液从婴儿的嘴里流了出来。

2 allergies   

n.[医]过敏症；[口]厌恶，反感；（对食物、花粉、虫咬等的）过敏症( allergy的名词复数 )；变态反应，变应性

参考例句：

• Food allergies can result in an enormous variety of different symptoms. 食物过敏会引发很多不同的症状。 来自辞典例句
• Let us, however, examine one of the most common allergies; hayfever. 现在让我们来看看最常见的变态反应的一种--枯草热。 来自辞典例句