Question: who is the father of the air force
[{'answer': 'William Lendrum Mitchell', 'provenance': [{'wikipedia_id': '184170', 'title': 'Billy Mitchell', 'start_paragraph_id': 1, 'start_character': 0, 'end_paragraph_id': 1, 'end_character': 24, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '184170', 'title': 'Billy Mitchell', 'start_paragraph_id': 1, 'start_character': 0, 'end_paragraph_id': 1, 'end_character': 158, 'bleu_score': 0.9271474438253491, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 805621707737612391}, 'section': 'Section::::Abstract.'}]}]