If you're reading this in a car, you may be feeling just a little bit uneasy4. Carsickness. Disgusting5.
Motion6 sickness can happen in a car, plane, amusement park ride7, or even in space. It all has to do with your sense of balance—where your body is, and how it's moving.
Lots of parts of your body work together to create your sense of balance. Your inner8 ears sense whether you're standing still, turning, moving forward or backwards, up or down, or side to side.
Your eyes see where your body is in relation to the world (if you are, for example, upside down). Your skin feels which part of your body is touching the ground—your feet or your bottom.
Your muscles9 and joints10 tell which parts of your body are moving and which are staying still. Your brain takes all that information and makes sense of it.
If the signals from different parts of your body disagree, your brain gets confused11, and you can feel dizzy12 and uneasy. You can even vomit.
So, when you sit in a car reading, your inner ears feel the curves and bumps13 of the moving car, but your eyes only see the page of the book—which doesn't look like it's moving at all.
Message from your brain: What is going on? So what can you do to avoid carsickness?
Don't read. Lean back against the headrest14 or seat back. Close your eyes. Open a window to get some fresh air. Drink something. Don't look out your side window at the passing scenery. Instead, look ahead at the horizon.
And if nothing helps, remember that you're not alone. Seventy percent of astronauts suffer from motion sickness. And they can't pull over15 at a rest stop and get out.
如果你在行驶的小车里阅读本文，你可能会感到不舒服——有点恶心，想吐。这就是晕车。
坐汽车、坐飞机，坐公园的游乐车，甚至在太空旅行，都有可能出现这种运动病。运动病与人的平衡感有关——平衡感告诉我们身处何处、如何在运动。
身体的很多部位共同协作才产生平衡感:内耳膜感觉到的是:你是一动不动地站着、还是在转身，是朝前朝后运动，还是向上向下、向左向右移动？
眼睛看到的是身体与周围世界的参照关系（如：你是否倒立）。皮肤感觉到的是身体的哪一个部位正与地面接触——是你的双脚还是你的臀部？
肌肉和关节感觉到的是身体的哪些部位在移动、哪些部位静止不动。大脑接收到所有这些信息之后，再加以分析、判断。
如果你身体各部位(传达给大脑)的信号互相不一致，那么大脑的思维就会出现紊乱，你就会感到头昏眼花、心里难受，甚至大呕狂吐。
想一想——当你在车里读书时，内耳膜感觉到的是汽车行驶时的拐弯和颠簸运动，而眼睛看到的却是一页页书：而书好像一动不动呢！（传给大脑的信息就不一致了！）
这时候，你脑子就会问：到底出了什么事？（把我弄糊涂了！）那么，如何避免晕车呢？
不要看书；干脆靠在头垫上，或者身子尽量往后坐；闭上眼睛；打开窗户呼吸新鲜空气；喝点饮料；不要透过身边的窗户扫视窗外稍纵即逝的风景。不妨看看远方的地平线。
如果这一切都无济于事，请记住：无可奈何的不只你一个。百分之七十的宇航员都饱受运动病之苦，他们甚至无法停靠某个站点以便走出船舱休养片刻（而你却可以）。
1． spin [spin] v．眩晕
2． carsickness n．晕车
3． avoid v．避免
4． uneasy ]adj．不安的
5． disgusting adj．令人作呕的
6． motion n．运动
7． amusement n．娱乐
amusement park ride公园的游乐车
8． inner adj．内部的
9． muscle n．肌肉
10．joint n．关节
11．confused adj．混乱的
12．dizzy adj．头晕眼花的
13．bump n．冲撞，颠簸
14．headrest n．（座椅的）头靠
15．pull over （口）把（车）停靠路边