Nostrils and Roses
鼻子在供氧过程中起着非常重要的作用，鼻子是外界氧气进入人体内部的重要通道，同时它还负责呼出体内的二氧化碳。我们可以将鼻子看作一个整体器官，但是因为鼻子的大部分功能都是在立体系统中完成的，所以我们需要两个鼻孔。
众所周知，我们有左右两个肺脏，但可能很少人知道，每一侧肺脏都是由其同侧相应的鼻孔控制的。
因此如果一个鼻孔堵塞，两侧的肺就会产生竞争，让人觉得难受、呼吸不畅。不仅如此，专关家认为两个鼻孔还能使呼吸运动更有效，进而推进整个机体的新陈代谢。用两个鼻孔透气使得每一个鼻孔可以轮换稍事休息，如果只用一个鼻孔透气，3小时就会感到疲劳。
两个鼻孔的生理结构有助于睡眠。在8小时以上的睡眠中如果保持一种睡姿不变，由于重力作用与站姿时相比发生了变化，一侧的鼻孔通常会闭塞。
因此，我们用两个鼻孔透气可以睡得更放松。由于睡眠中人对氧气的需求量减少，即使一个鼻孔暂时不通，只有另一个呼吸也不会造成呼吸不畅。
今天我们就一起听听两个鼻孔的重要性吧。

Take a Look in the mirror and ask yourself this: why do I have two nostrils. Two eyes, sure. Two ears, ok. But why two nostrils? Wouldn t one, big nostril do just as well?
Actually, no. First, one giant nostril would look really weird. And second, although they may look identical, each nostril actually smells a bit differently. For most people, nostrils take turns swelling and shrinking, meaning that at any given moment the rate at which a nostril inhales is not equal.
Let s say you re taking a walk and stop to sniff a rose. Your swollen nostril inhales the tiny, microscopic particles released by the rose at a relatively slower pace than the normal nostril, which inhales at a normal clip. This is important since chemicals that enter your nose and create smell, including rose particles, come in two basic types: those that dissolve slowly and those that dissolve more quickly.
In order for slow-dissolving rose chemicals to really work they have to enter the nose at a leisurely pace and kind of settle down. If they re rushed in on a fast stream of air too many pass right through the nose and don t contribute to that unique, rosy smell. The rose chemicals that dissolve quickly, meanwhile, like to charge in and spread out fast in order to really pack a punch. Since they inhale at different speeds, your nostrils allow both kinds of rose chemicals to do their thing.
So a rose may be a rose, but in order to really smell one you need two nostrils. One big one just won t do.