Question: when were ambulances first used in the us
[{'answer': 'In the late 19th century', 'provenance': [{'wikipedia_id': '21311092', 'title': 'History of the ambulance', 'start_paragraph_id': 24, 'start_character': 0, 'end_paragraph_id': 24, 'end_character': 24, 'bleu_score': 1.0, 'section': 'Section::::Mass transit use for emergency medical provision.\n'}]}, {'provenance': [{'wikipedia_id': '21311092', 'title': 'History of the ambulance', 'start_paragraph_id': 24, 'start_character': 0, 'end_paragraph_id': 24, 'end_character': 462, 'bleu_score': 0.9748377259086851, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 4367781467856055799}, 'section': 'Section::::Mass transit use for emergency medical provision.\n'}]}]