Question: when was the last time someone walked on the moon
[{'answer': 'Apollo 17', 'provenance': [{'wikipedia_id': '1971', 'title': 'Apollo 17', 'start_paragraph_id': 0, 'start_character': 0, 'end_paragraph_id': 0, 'end_character': 9, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}]