Question: who has the largest zoo in the united states
[{'answer': 'North Carolina Zoological Park', 'provenance': [{'wikipedia_id': '1471629', 'title': 'North Carolina Zoo', 'start_paragraph_id': 1, 'start_character': 4, 'end_paragraph_id': 1, 'end_character': 34, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '1471629', 'title': 'North Carolina Zoo', 'start_paragraph_id': 1, 'start_character': 4, 'end_paragraph_id': 1, 'end_character': 673, 'bleu_score': 0.507619254046182, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 2277973390948132034}, 'section': 'Section::::Abstract.'}]}]