Question: what is the longest stone arch bridge in the world
[{'answer': 'The Rockville Bridge', 'provenance': [{'wikipedia_id': '890995', 'title': 'Rockville Bridge', 'start_paragraph_id': 1, 'start_character': 0, 'end_paragraph_id': 1, 'end_character': 20, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '890995', 'title': 'Rockville Bridge', 'start_paragraph_id': 1, 'start_character': 0, 'end_paragraph_id': 1, 'end_character': 272, 'bleu_score': 0.814568309231332, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 11177462053546188606}, 'section': 'Section::::Abstract.'}]}]