Sentence:  The severe yet harmonious vases of the previous fifty years , the Strong Geometric style of the late ninth century , display as firm a mastery of the principles underlying Geometric pottery ; but artists now <WSD>were</WSD> ready to refine and elaborate their inheritance . 
Meaning of the word marked with <WSD> tags:  have the quality of being; (copula, used with an adjective or a predicate noun)