2 Words to use with sturdiest

My own idea is that England is fighting for it in this struggle; and starting unready against a foe which was ready, as the free peoples always have done, she was fighting for time and experience before she could strike her sturdiest blows.

How little music has to do with one's state of mind, may be seen from the fact that in his weak and complaining despair, he composed one of his sturdiest works, "Kampf und Sieg."

2 Words to use with  sturdiest