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 key to', Sentence: 'As present processes are thought to explain all past events , the Uniformitarianism slogan is " the present is the key to the past . "'
key

Given Relationship: 'be son of', Sentence: 'Peter is called son of John in John 21:15 and Barjona in Matt 16 :17 .'
son

Given Relationship: 'beat', Sentence: 'Do people seriously think that because the Giants beat the Redskins , and the Redskins beat the Cowboys , that somehow the Giants have overtaken the Cowboys ?'
beat