Definition: 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.
Input: Sentence: 'Meanwhile , a key Muslim ally of the United States , Saudi Arabia , produced 15 of the 19 Sept. 11 hijackers--and Bin Laden .', Argument/Subject 1: 'saudus arabium', Argument/Subject 2: 'unite state'
Output:
be ally of