题目

如图2所示，这是圆桌正上方的灯泡（看作一个点）发出的光线照射桌面后，在地面上形成阴影（圆形）的示意图.已知桌面的直径为1.2m，桌面距离地面1m，若灯泡距离地面3m，则地面上阴影部分的面积为（   ）                   A、0.36m2    B、0.81m2     C、2m2      D、3.24m2   答案：BWalk your way to better healthLeft foot, right foot, left foot, right foot ... you can travel fast or slow. The movement of your f【1】gets you where you need to go. But it also gets you so much more! Walking is simple e【2】and good for almost everyone. Best of all, it’s free!Walking helps you in many ways. First it makes your heart stronger. Studies s【3】 walking reduces (降低) your chance of heart problems. Walking quickly for 30 m【4】 a day also helps control high blood pressure. It can reduce your chance of having other serious problems, too.As time goes by, people become old, and t【5】 brains don’t work as well as before. I【6】 old people walk six miles or more every week, they can keep their brains in a better condition.Walking helps your mental (精神的) health, too. P【7】one foot in front of the other isn’t difficult. You don’t have to think about it, so you can pay attention to o【8】 things. You can consider problems or think of ideas. You can think over conversations again or just remember funny things.You can make walking part of your day. Instead of t【9】 the lift, walk. You can even have walking meetings. They are what they sound l【10】. Instead of sitting, you walk and talk things over.Make walking a habit, and see how it makes you feel.