sentences:  Cui Renshi was born in the 580s, during the reign of Emperor Wen in the Sui dynasty.He was from Ding Prefecture (定州, roughly modern Dingzhou, Hebei).Early in the reign of Emperor Gaozu (r. 618–626), the founder of the Tang dynasty, Cui Renshi passed an imperial examination and was made the military advisor to the prefect of Guan Prefecture (管州, part of modern Zhengzhou, Henan).