company news about What is a wheel?

The wheel is gradually discovered in the labor practice of carrying things. In primitive society, human ancestors made a living by collecting and hunting. At the beginning, they got Limited food and could easily bring it back with them. So someone came up with an idea. He picked up a few broken thick branches from the ground, connected them with vines, and then put the prey on them. He grabbed two long branches with both hands and dragged them away, which was much lighter than carrying them on his shoulders. I also thought of using a wooden stick with one end on my shoulder and the other end on the ground to hang heavy objects in the middle of the stick and pull them away, which is also less labor-saving than carrying them by hand. People put two sticks side by side, tied a piece of cloth in the middle, holding two sticks with both hands and dragging the other end on the ground. The above is a kind of "light pry" originally invented by people, which is characterized by sliding on the ground with the help of a sliding rod.