★英語聽力頻道為大家整理的英語聽力練習(xí)材料：嘴唇為何會干，供大家參考。更多閱讀請查看本站英語聽力頻道。
我們首先看下嘴唇表面與我們的身體其余部分皮膚的不同。
Let's start by reviewing the ways in which the surface of our lips is different from the surface of the skin on the rest of our bodies.
基本而言,我們的嘴唇由保護我們嘴部的相同粘液膜組成。
Basically, our lips are made of the same mucus membrane that coats the inside of our mouths.
這意味著兩件事。
This means two things.
首先,我們的嘴唇?jīng)]有同身體相同的外層保護皮膚。
嘴唇.jpg
First, our lips don't have the same protective outer layer as the skin elsewhere on our bodies.
這一層能夠抵擋水分蒸發(fā),而它的缺乏意味著我們的嘴唇皮膚只能留存較少的液體。
This layer is part of the barrier to evaporation, and its absence means our lip skin retains less fluid.
第二,我們的嘴唇?jīng)]有普通的皮膚所具有的腺體和色素。
Second, our lips don't have the same glands and pigments as ordinary skin.
比如嘴唇?jīng)]有也有助于防止水分蒸發(fā)的油腺,而且嘴唇含有更少的黑色素,這種色素能夠幫助保護皮膚免受太陽灼傷。
For example, lips don't have oil glands, which also help keep moisture from evaporating, and they contain less melanin, the pigment that helps protect our skin from sunburn.
我們首先看下嘴唇表面與我們的身體其余部分皮膚的不同。
Let's start by reviewing the ways in which the surface of our lips is different from the surface of the skin on the rest of our bodies.
基本而言,我們的嘴唇由保護我們嘴部的相同粘液膜組成。
Basically, our lips are made of the same mucus membrane that coats the inside of our mouths.
這意味著兩件事。
This means two things.
首先,我們的嘴唇?jīng)]有同身體相同的外層保護皮膚。
嘴唇.jpg
First, our lips don't have the same protective outer layer as the skin elsewhere on our bodies.
這一層能夠抵擋水分蒸發(fā),而它的缺乏意味著我們的嘴唇皮膚只能留存較少的液體。
This layer is part of the barrier to evaporation, and its absence means our lip skin retains less fluid.
第二,我們的嘴唇?jīng)]有普通的皮膚所具有的腺體和色素。
Second, our lips don't have the same glands and pigments as ordinary skin.
比如嘴唇?jīng)]有也有助于防止水分蒸發(fā)的油腺,而且嘴唇含有更少的黑色素,這種色素能夠幫助保護皮膚免受太陽灼傷。
For example, lips don't have oil glands, which also help keep moisture from evaporating, and they contain less melanin, the pigment that helps protect our skin from sunburn.