英语时差：为什么闭着眼睛很难单脚站立？（上）

Try standing on one foot. Not so hard, you say? Try it with your eyes closed. Aha! Suddenly things got much harder. With eyes closed you may begin to wobble and tilt, but as soon as you open them, things get easier again. You can achieve this same effect by standing on one foot in a completely darkened room. Don’t laugh until you’ve tried it! what's going on? Well, you may have heard that our sense of balance is centered in our ears. To a certain extent, this is true. In each ear is a series of organs that respond to various kinds of motion. Some sense forward and backward motion, some rotation.