Question: who won the gold medal for 400 metres run at two consecutive olympic games
[{'answer': 'Michael Johnson', 'provenance': [{'wikipedia_id': '41876800', 'title': '400 metres at the Olympics', 'start_paragraph_id': 2, 'start_character': 224, 'end_paragraph_id': 2, 'end_character': 239, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '41876800', 'title': '400 metres at the Olympics', 'start_paragraph_id': 3, 'start_character': 0, 'end_paragraph_id': 3, 'end_character': 510, 'bleu_score': 0.9294832414907921, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 9979154403889377907}, 'section': 'Section::::Abstract.'}]}]