Sentence:  Among the other solo ballet dancers of the evening , Elisabeth Carroll and Ivan Allen <WSD>were</WSD> particularly impressive in their roles in `` The Duel '' , a work that depends so much upon the precision and incisiveness of the two principal combatants . 
Meaning of the word marked with <WSD> tags:  have the quality of being; (copula, used with an adjective or a predicate noun)