她凭借坚定的决心克服了所有困难。

Her ___steadfastness helped her overcome all the challenges.

在困难时期，他表现出了对朋友坚定不移的忠诚。

During tough times, he showed remarkable ___steadfastness to his friends.

尽管面临诸多困难，他的坚定使他最终实现了梦想。

Despite many challenges, his ___steadfastness helped him achieve his dream in the end.