Question: how many years did it take the united states to become involved in world war ii
[{'answer': 'first two years', 'provenance': [{'wikipedia_id': '4653534', 'title': 'Military history of the United States during World War II', 'start_paragraph_id': 1, 'start_character': 168, 'end_paragraph_id': 1, 'end_character': 183, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}]