Question: who won the world series last year in 2017
[{'answer': 'Houston Astros', 'provenance': [{'wikipedia_id': '50635427', 'title': '2017 World Series', 'start_paragraph_id': 1, 'start_character': 323, 'end_paragraph_id': 1, 'end_character': 337, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}]