Question: who fought in the battle of vimy ridge
[{'answer': 'Canada', 'provenance': [{'wikipedia_id': '70435', 'title': 'Battle of Vimy Ridge', 'start_paragraph_id': 69, 'start_character': 24, 'end_paragraph_id': 69, 'end_character': 30, 'bleu_score': 1.0, 'section': 'Section::::Commemoration.\n'}]}, {'answer': 'United Kingdom'}, {'answer': 'German Empire'}]