Sentence:  The very firmness of her convictions and logical clearness of her arguments captivated and stimulated him to make greater efforts ; usually , this <WSD>is</WSD> most exasperating to men , who expect every woman to verify their preconceived notions concerning her sex , and when she does not , immediately condemn her as eccentric and unwomanly . 
Meaning of the word marked with <WSD> tags:  have the quality of being; (copula, used with an adjective or a predicate noun)