Question: who played marty in back to the future
[{'answer': 'Michael J. Fox', 'provenance': [{'wikipedia_id': '42993', 'title': 'Back to the Future', 'start_paragraph_id': 1, 'start_character': 134, 'end_paragraph_id': 1, 'end_character': 148, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '42993', 'title': 'Back to the Future', 'start_paragraph_id': 1, 'start_character': 0, 'end_paragraph_id': 1, 'end_character': 619, 'bleu_score': 0.539369362378269, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 10059139842692326448}, 'section': 'Section::::Abstract.'}]}]