Question: when did the seven dwarfs mine train open
[{'answer': 'May 28 , 2014', 'provenance': [{'wikipedia_id': '31215824', 'title': 'Seven Dwarfs Mine Train', 'start_paragraph_id': 4, 'start_character': 426, 'end_paragraph_id': 4, 'end_character': 439, 'bleu_score': 1.0, 'section': 'Section::::History.\n'}]}, {'provenance': [{'wikipedia_id': '31215824', 'title': 'Seven Dwarfs Mine Train', 'start_paragraph_id': 1, 'start_character': 0, 'end_paragraph_id': 1, 'end_character': 501, 'bleu_score': 0.9766041382465441, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 17357256277898370310}, 'section': 'Section::::Abstract.'}]}]