Sentence:  Not that it is all funny , by any means , though some of it <WSD>is</WSD> definitely so , but simply that the dancers are young and handsome , high-spirited and communicative , and the program itself is as vivacious as it is varied . 
Meaning of the word marked with <WSD> tags:  have the quality of being; (copula, used with an adjective or a predicate noun)