instruction:
From the given sentence, extract the phrase (often noun or verb) that carries the given relationship. The generated phrase should be present in the sentence.
question:
Given Relationship: 'be service of', Sentence: 'See a list of publications by Mayo Clinic authors on mitral valve disease on PubMed , a service of the National Library of Medicine .'
answer:
service


question:
Given Relationship: 'say unto', Sentence: 'And the LORD said unto Moses , The man shall be surely put to death : all the congregation shall stone him with stones . "'
answer:
unto


question:
Given Relationship: 'be man of', Sentence: 'David was a man after God 's own heart , and yet he had sins of his youth which reproached him .'
answer:

man