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.

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 .'
service

Given Relationship: 'meet', Sentence: 'When Harry met Sally ... - Is it love or lust ?'
met

Given Relationship: 'operate in', Sentence: 'The panel discussion will be moderated by Professor Tim Davis of the Wake Forest University School of Law , and include the counsels of several prominent multinational companies that operate successfully in the United States .'

operate