最恼人的一件事就是青春期脸上长痘痘。

Not only do they make their entrance just at the time when people are most self-conscious, but they come and go for the rest of your life.

在人们最有自我意识的时候会冒痘痘，而且痘痘可能会在你脸上保留一辈子。

It would almost be better to have a hairy face.

也许脸上长满毛会更好。

Ironically, the general covering of our bodies in hair---what we call "fur" on other animals---is at the root of our problem with acne.

讽刺的是，我们身上的体毛，就是我们所说的其他动物的“皮毛”——就是我们脸上长粉刺的根源所在。

In the course of evolution human beings lost their entirely hairy faces and now have a lot of exposed skin there: even a bearded man with bushy eyebrows has much of his face bare.

在进化的过程中，人类完全失去了他们毛茸茸的面孔，进而暴露出大部分的皮肤：甚至是浓眉大眼的长满胡须的男人，他的脸都是光滑的。

The structures in the facial skin that once gave rise to hair, however, have not disappeared entirely: many still contain tiny vestigial hairs which do not grow.

面部皮肤结构一旦催生出毛发，就不能完全消失：很多还包含着微小残留的长不出来的毛发。

That means there is nothing to open up the pore itself; and that means the pore is a great place for oils, dirt and bacteria to get clogged.

那就意味着和毛孔本身无关，而且意味着毛孔能被油脂，污垢和细菌堵塞。

You can get zits anywhere vestigial follicles become clogged.

残留毛囊堵塞的地方就会长有青春痘。

The big culprit on faces, though, isn't dirt so much as an internally-produced substance called sebum that makes the skin cells shed inside the pores.

不过脸部的罪魁祸首与其说是不干净，倒不如说是一种内部产生的物质，皮脂，使得皮肤毛孔内的细胞脱落。

These dead cells, unable to flake away, collect until they become an irritation to the pore.

这些死细胞，无法自动脱落，一直累积直到其对毛孔产生刺激作用。

At this point the body reacts in a miniature version of the way it deals with any other invasion: it sends white blood cells to the site to attack the invading body.

此时人体会减弱其他任何形式的入侵，从而它会将白细胞送至机体来抵抗受侵细胞。

The result is a mild inflammation at the scene of battle. That inflammation is the zit.

结果就是轻度炎症在作怪。而那炎症就是青春痘。

So evolution, while having cleaned our hairy faces, gave us pimply skin instead.

所以进化在清理我们多毛的面孔的同时，也会使我们的皮肤长有粉刺。