Sentence:  Competitors came to receive higher percentage of General Motors business in later years , but it <WSD>is</WSD> `` likely '' that this trend stemmed `` at least in part '' from the needs of General Motors outstripping du Pont 's capacity . 
Meaning of the word marked with <WSD> tags:  have the quality of being; (copula, used with an adjective or a predicate noun)