Your brain controls everything you do. It makes it1for you to think, learn, create and feel; to blink (眨眼) and breathe and for your heart to beat—this fantastic control center is your2 .
Can this small grey organ (器官) , which 3 less than one and a half kilos, really do so much? Amazingly, your brain contains about 100 billion neurons (神经元) —it would 4you over 3,000 years to count them all. Believe it or not, the 5 in your brain never stops. Your neurons create and send more messages than all the phones in the world. And although one neuron6only a little electricity, all your neurons together can 7 enough electricity to supply a light bulb (灯泡).
So exactly how fast does your brain work? Well, imagine this: A bee lands on your foot. Neurons in your skin send this information to your brain8a speed of more than 240 kilometers per hour. Your brain then uses 9 neurons to send the message back to your foot to shake the bee off 10. These neurons can send this11at more than 320 kilometers per hour. No computer has your brain's unbelievable ability to deal with the amount of information coming from your eyes, ears and other sensory organs.
But how does your brain allow you12 things that you will use in the future? The structure (结 构) of your brain changes every time you have a new13, remember or learn something. For example, riding a bike seems impossible at first, 14 soon you are able to do it. How? As you practice, your brain 15“bike riding” messages again and again. Soon, the actions are learned and you are able to ride a bike easily from then on.
