坚忍不拔

Explanation: Difficult to describe in difficult circumstances will a firm, unwavering. 　　Usage: Supplemental; as predicate, attributive; with a compliment 　　Source: Su Song, "Chao Cuo theory": "ancient stand of those great things, not only the world's only super, there is always indomitable ambition." 　　Examples: Regardless of the difficulties encountered in life, we have ~, indomitable spirit. Thesaurus:  granite, one's mind is perturbed to forcibly restrain one's temper, keep one's end up, Gan shi Xiaoyi, adhere not to change, be willing to toil