Sentence:  Clearly the most provocative plays <WSD>are</WSD> all imported originals - A Taste of Honey , by Britain 's young ( 19 when she wrote it ) Shelagh Delaney ; Becket , by France 's Jean Anouilh ; The Hostage ( closed ) , by Ireland 's Brendan Behan . 
Meaning of the word marked with <WSD> tags:  have the quality of being; (copula, used with an adjective or a predicate noun)