Question: when was the rialto bridge in venice built
[{'answer': 'the 12th century', 'provenance': [{'wikipedia_id': '974321', 'title': 'Rialto Bridge', 'start_paragraph_id': 1, 'start_character': 243, 'end_paragraph_id': 1, 'end_character': 259, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '974321', 'title': 'Rialto Bridge', 'start_paragraph_id': 1, 'start_character': 0, 'end_paragraph_id': 1, 'end_character': 316, 'bleu_score': 0.7778538925793901, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 11100943455221133830}, 'section': 'Section::::Abstract.'}]}]