TASK 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.
PROBLEM: Sentence: 'He lives in the U.S. Pacific Northwest between the cities of Seattle , Washington , and Vancouver , British Columbia .', Argument/Subject 1: 'seattle', Argument/Subject 2: 'pacific northwest'

SOLUTION: be city in

PROBLEM: Sentence: 'Gradually the official language of Ukrainian provinces under Poland was changed to Polish , while the upper classes in the Russian part of Ukraine used Russian widely .', Argument/Subject 1: 'polish', Argument/Subject 2: 'poland'

SOLUTION: be language of

PROBLEM: Sentence: 'The heliocentric theory stated that the Earth revolves around the Sun , as opposed to the geocentric theory that Sun revolves around the Earth .', Argument/Subject 1: 'earth', Argument/Subject 2: 'sun'

SOLUTION:
revolve around