Sentence:  His denials of extensive reading notwithstanding , it <WSD>is</WSD> no doubt safe to assume that he has spent time schooling himself in Southern history and that he has gained some acquaintance with the chief literary authors who have lived in the South or have written about the South . 
Meaning of the word marked with <WSD> tags:  have the quality of being; (copula, used with an adjective or a predicate noun)