All herbivores in the world have sharp teeth. Cattle are a little special and different, with only lower teeth and no upper teeth. There is a folk story about this special-shaped cow. According to legend, a long time ago, cows, like sheep, horses and other herbivores, all had sharp teeth up and down. Cutting grass is not slower than sheep, and cutting material is not worse than horses. Among herbivores, its teeth are among the best. The cow is also very satisfied with this sharp tooth and boasts to other animals from time to time. At that time, cows and people lived alone. People raise cattle, and cows help people plow and rake the fields, just like people's right hand and left hand. One day, when the cow was ploughing hard in the field, the tiger, the king of beasts, passed by. He saw the cow pulling a heavy wooden plow, sweating and covered in mud, trudging forward step by step. He sneered at the cow and said, "Mr. Niu, you have such a big size, such great strength and long horns like swords. You should not only pull them out. Speaking of this, it sighed: "Well, what you did, in my opinion, is not commensurate with yourself." Then he burst out laughing proudly. While pulling the plow, the cow listened carefully to the tiger laughing at itself. After listening to the tiger, it said to the tiger without thinking, "I don't fight with people's mouths." "But ... to be honest, I am not as good as people in all aspects, not only as good as people, but also far from it." At this point, the cow pulled the plow away without saying a word. At this time, the tiger, who was watching the cow quietly plow the fields, smiled and said to the cow, "I'm not asking you to compete with others, I mean you are much stronger than me ..." "I know whether it is strong or not. If you don't believe me, find someone to tie it up. At that time, you will know who is capable, "said the cow and the tiger." The tiger, who has always been proud, agreed to this in order to show his skill. The self-righteous tiger respectfully said to people, "Brother Tian Kai, please tie me up like an ox and see who is more capable, me or the ox." After that, it fell to the ground and was tied up obediently. The driver released the cow, untied the cow's rope and tied the tiger up. When a pack of cigarettes came down, the tiger's four legs and four hands were tied iron and iron. After it was tied, he looked through it to see if there was any looseness. After reading it, he picked up his two feet for plowing, raised them above his head, aimed at the tiger and rowed hard. One by one, the tigers were beaten and bleeding. At this time, it can't move or walk, so it has to bow its head and give up, begging for mercy: "Brother Tian Kai, I give up, please don't fight." Say it, hum it. "Ha ha ha ....." The cow standing by could not help laughing when she saw the ugly appearance of the tiger giving up begging for mercy. At this time, because he was happy, he just smiled and didn't care too much. He slipped and jumped into the field from the ridge. This fall, there is no slap, only the mouth on the ground. As soon as he looked up, his mouth suddenly hurt like hell, so he wanted to open his mouth to see if there was any damage. Strange to say, as soon as the mouth is opened, the upper teeth fall off one by one and fall to the ground neatly. Looking at the shiny teeth, it began to cry sadly. Cows have never grown new teeth since they lost their teeth. From generation to generation, until today, there are no teeth.