unyielding

尽管面临诸多挑战，她依然保持坚定的态度。

Despite many challenges, she remained ___unyielding in her stance.

这块花岗岩非常坚硬，锤子都敲不碎。

The ___unyielding granite rock couldn't be broken even with a hammer.

他固执地拒绝让步，使得谈判陷入僵局。

His ___unyielding refusal to compromise led to a deadlock in the negotiation.