Give some inspiration: when it comes to leverage, Archimedes comes to mind first. One day, after a long drought, Archimedes was walking along the Nile. He saw that it was quite difficult for farmers to carry water to irrigate their land. After thinking, he invented a tool, which uses the lever principle of water to rotate and suck in the water pipe under the action of screw. Later people called it "Archimedes spiral water lifter". Archimedes said, "If you give me a fulcrum and a hard stick long enough, I can move the whole earth." . Lever is a kind of power-assisted tool. When a force acts on two points and makes it rotate around the third point, it can transfer and change the force or motion. The application of lever principle is everywhere in life, such as pushing the door, opening the window, opening the bottle cap, brushing your teeth and driving. Therefore, we should be good at using scientific knowledge to benefit mankind.