 Complete the following phrase:  Guan Ping appears in the 14th century historical novel Romance of the Three Kingdoms by Luo Guanzhong. He is the second son of Guan Ding 關定, a farmer. His elder brother is Guan Ning 關寧. Guan Yu encounters Guan Ding and his family during his journey across five passes to find Liu Bei. He is so impressed with Guan Ping on first sight that he accepts him as his foster son. During the Battle of Ru, Guan Ping, Guan Yu and Zhou Cang lead 300 men to rescue Liu Bei, who is under attack by Cao Caos general Zhang He. Guan Ping participates in some of Liu Beis subsequent military exploits, including the Battle of Bowang against Cao Caos general Xiahou Dun, and the 