Question: when did the first train in the world
[{'answer': 'c. 700 BC', 'provenance': [{'wikipedia_id': '398236', 'title': 'Timeline of railway history', 'start_paragraph_id': 2, 'start_character': 12, 'end_paragraph_id': 2, 'end_character': 20, 'bleu_score': 1.0, 'section': 'Section::::BC.\n'}]}, {'provenance': [{'wikipedia_id': '398236', 'title': 'Timeline of railway history', 'start_paragraph_id': 2, 'start_character': 0, 'end_paragraph_id': 2, 'end_character': 556, 'bleu_score': 0.979054689945215, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 17021015096952688183}, 'section': 'Section::::BC.\n'}]}]