Question: the first electron acceptor in cellular respiration is
[{'answer': 'oxygen', 'provenance': [{'wikipedia_id': '102871', 'title': 'Cellular respiration', 'start_paragraph_id': 2, 'start_character': 187, 'end_paragraph_id': 2, 'end_character': 193, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '102871', 'title': 'Cellular respiration', 'start_paragraph_id': 6, 'start_character': 0, 'end_paragraph_id': 6, 'end_character': 928, 'bleu_score': 0.986969988197764, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 12054598596076461995}, 'section': 'Section::::Aerobic respiration.\n'}]}]