Given a sentence and two mentions from the text (arguments), indicate a phrase (a verb or noun phrase) that describes the relationship between the provided arguments.

Q: Sentence: 'But Obama supporters can have at least some solace to know that there has been no recent Pennsylvania poll with McCain leading Obama .', Argument/Subject 1: 'mccain', Argument/Subject 2: 'obama'

A: lead
****
Q: Sentence: 'McCullough focusses on Mary , the plain and pontificating middle sister .', Argument/Subject 1: 'mccullough', Argument/Subject 2: 'mary'

A: focus on
****
Q: Sentence: 'Lester Brown is the president of the Earth Policy Institute , a nonprofit interdisciplinary research organization based in Washington D.C. he us the author of Plan B : Rescuing a Planet Under Stress and a Civilization in Trouble .', Argument/Subject 1: 'lester brown', Argument/Subject 2: 'earth policy institute'

A:
be president of
****