百折不回

Explanation: Fold: frustration. Metaphor of a strong will, no matter how many times by _set_backs, wavering back. 　　Usage: Partial official; as the predicate attribute; describe the strong-willed 　　Source: "History of the Ming-style plow He Tengjiao Biography of Qu": "Cardiff and righteousness will then see the poor, such as the two had tried to death, extravagant with Janus-faced, who carry the so-called tough and focused." 　　Examples: Dedicated from the beginning, ~. (Qing Yao Ying, "Fu Jun Yang instruments of Poetry") Thesaurus:  constancy, Indomitable, Make light of Sway, keep one's end up, persist in sth.