坚强不屈

Explanation: Qu: yield. Tenacity, fortitude, not to yield. 　　Usage: Supplemental; as the predicate attribute; with compliment, determined not to bow 　　Source: Xun "Xunzi Law Line": "Kennedy just and unbending righteousness." Thesaurus:  be enduring as the universe, as long as the heaven and earth endure, adamantine, Hao ran Qi, Candour Not A, constancy not to change, Jian-Gang unyielding, to give rewards or punishment strictly and impartially Antonym Group:  Let bygones be bygones, Do not chase past