Sentence:  It <WSD>is</WSD> not that the facts of the persecution were unavailable ; most of the information elicited in Jerusalem had been brought to the surface by the numerous War Crimes tribunals and investigating commissions , and by reports , memoirs , and survivors ' accounts . 
Meaning of the word marked with <WSD> tags:  have the quality of being; (copula, used with an adjective or a predicate noun)