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.

[Q]: Given Relationship: 'be mayor of', Sentence: 'And former New York mayor Rudy Giuliani suggested men of a certain age get checked for prostate cancer , following in the footsteps of former US senator Bob Dole , whose appearances in Viagra ads are credited with persuading more men to discuss erectile dysfunction with their doctors .'
[A]: mayor


[Q]: Given Relationship: 'be elect by', Sentence: 'Our Board of Trustees serve in a voluntary capacity and are elected by our voluntary branches or co-opted for their expertise .'
[A]: elected


[Q]: Given Relationship: 'be president of', Sentence: 'Richard Milhous Nixon , the thirty-seventh President of the United States became President in 1969 after defeating Lyndon Johnson 's Vice-President , Hubert Humphrey , in one of the closest elections in US history .'
[A]:
President