Question: which city was known as porkopolis after its slaughterhouse district
[{'answer': 'Cincinnati , Ohio', 'provenance': [{'wikipedia_id': '1758558', 'title': 'Union Stock Yards', 'start_paragraph_id': 27, 'start_character': 363, 'end_paragraph_id': 27, 'end_character': 380, 'bleu_score': 1.0, 'section': 'Section::::History.:Back of the Yards Community.\n'}]}, {'provenance': [{'wikipedia_id': '1758558', 'title': 'Union Stock Yards', 'start_paragraph_id': 27, 'start_character': 0, 'end_paragraph_id': 27, 'end_character': 1200, 'bleu_score': 0.965131853228063, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 16326515090736135038}, 'section': 'Section::::History.:Back of the Yards Community.\n'}]}]