The ancients called arrows "arrows". The arrow is called dysprosium or dysprosium. All kinds of crossbows use arrows. It can be said that the arrow and the bow are contemporary products. The earliest arrow was very simple. It was cut into a certain length with a tree stick or bamboo pole and sharpened at one end. The real origin of the arrow should be the stone age of primitive society. People grind stone pieces, bones or shells into sharp shapes and install them at one end of the shaft to make arrows with stone arrows, bone arrows or shell arrows, which is a big step forward compared with arrows cut with wooden sticks and bamboo poles.