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 battle', Sentence: 'I nietzsche BACTRIM was battling Lyme , BACTRIM got in same tempra .'
battling

Given Relationship: 'be president of', Sentence: 'Tomorrow Barack Obama will become president of the United States .'
president

Given Relationship: 'be son of', Sentence: 'David and Tammy Skinner of Troy , Ill. , announce the engagement of their daughter , Misty Michelle Skinner , to Jesse William Minnick , son of Chuck and Diane Fritcher of Herrin , Ill .'

son