Ke, ke, Conghe Congdou. Original meaning: category, grade. Use a bucket to measure the grains to distinguish the types of grains. (1) Knowing. From the grain, from the fight. "Dou" means "quantity". Together they refer to measuring and classifying the grades of millet. Original meaning: category, grade. (2) With the original meaning [sort], it has multiple meanings in the dictionary and has three parts of speech: noun, verb and adjective. In biology, it is also one of the biological taxonomic units located between order and genus.