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.

Example Input: Sentence: 'October birthstone , Pink Tourmaline set in 14K yellow frame with 14K rose , 14K white and 18K yellow gold .', Argument/Subject 1: 'tourmaline', Argument/Subject 2: 'october'
Example Output: be birthstone of

Example Input: Sentence: 'Horus was the son of Osiris and Isis .', Argument/Subject 1: 'horus', Argument/Subject 2: 'isis'
Example Output: be son of

Example Input: Sentence: 'On January 20 , Barack Obama will become the 44th president of the United States .', Argument/Subject 1: 'obama', Argument/Subject 2: 'president'
Example Output:
become