unflinching

他带着坚定不移的决心接受了这个挑战。

He accepted the challenge with ___unflinching determination.

尽管面临诸多挑战，她依然坚定不移地追求自己的梦想。

Despite many challenges, she remains ___unflinching in pursuing her dreams.

尽管敌人火力凶猛，士兵们依然表现出无畏的勇气。

Despite the enemy's fierce fire, the soldiers showed ___unflinching courage.