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 president of', Sentence: 'Afghanistan president Hamid Karzai met Prime Minister Manmohan Singh at the Hyderabad House in New Delhi on Monday .'
president

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 language in', Sentence: 'Language English and French are Canada 's two official languages with English being the predominant language in British Columbia .'

language