Question: when did the east and west railroads meet
[{'answer': 'May 10 , 1869', 'provenance': [{'wikipedia_id': '36541', 'title': 'First Transcontinental Railroad', 'start_paragraph_id': 132, 'start_character': 31, 'end_paragraph_id': 132, 'end_character': 44, 'bleu_score': 1.0, 'section': 'Section::::Construction.:The "Last Spike" ceremony.\n'}]}, {'provenance': [{'wikipedia_id': '36541', 'title': 'First Transcontinental Railroad', 'start_paragraph_id': 132, 'start_character': 0, 'end_paragraph_id': 132, 'end_character': 879, 'bleu_score': 0.830426754818204, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 3114988120692551443}, 'section': 'Section::::Construction.:The "Last Spike" ceremony.\n'}]}]