"Jian" is a standard first-class word in modern Chinese, which was first seen in Xiao Zhuan period of Qin Dynasty. Its basic meaning is a ditch with running water between mountains, such as streams and mountain streams, and its extended meaning is valleys and valleys, such as streams and streams.
After Qin Shihuang unified the six countries (in the first 222 years), the unified measurement implemented the policy of "words with the same language, cars with the same track", and Prime Minister Li Si was in charge. On the basis of the original seal script used by Qin, he simplified it and created a unified Chinese writing form. Popular from the Qin Dynasty to the end of the Western Han Dynasty (about 8 AD), it was gradually replaced by official script. But because of its beautiful font and long ancient rhyme, it has always been favored by calligraphers.