Question: who built the first nuclear reactor the atomic pile
[{'answer': 'Enrico Fermi', 'provenance': [{'wikipedia_id': '1118396', 'title': 'Chicago Pile-1', 'start_paragraph_id': 1, 'start_character': 192, 'end_paragraph_id': 1, 'end_character': 204, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'answer': 'the Metallurgical Laboratory', 'provenance': [{'wikipedia_id': '1118396', 'title': 'Chicago Pile-1', 'start_paragraph_id': 1, 'start_character': 633, 'end_paragraph_id': 1, 'end_character': 661, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '1118396', 'title': 'Chicago Pile-1', 'start_paragraph_id': 1, 'start_character': 30, 'end_paragraph_id': 1, 'end_character': 832, 'bleu_score': 0.562369205936988, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 11112007786841098560}, 'section': 'Section::::Abstract.'}]}]