Question: who defeated the last song emperor of china
[{'answer': 'Kublai Khan', 'provenance': [{'wikipedia_id': '56978', 'title': 'Song dynasty', 'start_paragraph_id': 2, 'start_character': 1353, 'end_paragraph_id': 2, 'end_character': 1364, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '56978', 'title': 'Song dynasty', 'start_paragraph_id': 2, 'start_character': 0, 'end_paragraph_id': 2, 'end_character': 1727, 'bleu_score': 0.8717741047222791, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 945139537220472493}, 'section': 'Section::::Abstract.'}]}]