Who can tell me something about Du Fu's Biography of Li Chaoba's Little Powder (in detail)?

"Kuxian" and "Guanghe" are two monuments, which are famous for their exquisite calligraphy. This sentence is about the calligraphy advocated by Kuxian and Guanghe, which is similar to the following "The book is expensive and thin, and the spirit is interlinked". "

"Shang Shu Han chooses wood, riding Cao Cai has neighbors." Han Zemu and Cai were both famous calligraphers in Tang Dynasty and Tang Dynasty. They joined the army respectively. Later, there was a saying that "Chao chose his second son as his third son", which showed that he was as famous as these two men.