自从有人发现了杠杆原理之后,人类在从事体力劳动中都积极发挥它的作用。从杠杆原理的发挥,其后又发现了滑轮原理,人们懂得了把大小不同的滑轮加以组合,就可以用较小的力量举起较重的物体。今天,人们运用这些原理,制造出起重机,一个人坐在起重机的座垫上,可以移动几百吨的钢梁。可见,人类的发展,社会的进步,世间上的文明均可以相互影响和利用,从而升华到新的文明。如此不断的推进,社会才能发展和进步。大发明家爱迪生说:“要想成功就必须利用别人的 Since people discovered the principle of leverage, humans have actively played its role in physical labor. From the lever principle, the principle of pulley was discovered later. People learned that combining pulleys of different sizes can lift heavier objects with less force. Today, people use these principles to make cranes. One can sit on the seat of a crane and move hundreds of tons of steel beams. It can be seen that the development of mankind, the progress of society, and the civilization of the world can all influence and utilize each other and thus sublimate into a new civilization. With this constant advancement, the society can develop and progress. The great inventor Edison said: ”To succeed, you must use someone else’s