Sentence:  Third , the significance of the vocational courses is that those enrolled <WSD>are</WSD> keenly interested in the work ; they realize the relevance of what they are learning to their future careers , and this sense of purpose is carried over to the academic courses which they are studying at the same time . 
Meaning of the word marked with <WSD> tags:  have the quality of being; (copula, used with an adjective or a predicate noun)