Question: when did the us join world war ii
[{'answer': '1941', 'provenance': [{'wikipedia_id': '4653534', 'title': 'Military history of the United States during World War II', 'start_paragraph_id': 1, 'start_character': 128, 'end_paragraph_id': 1, 'end_character': 132, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '4653534', 'title': 'Military history of the United States during World War II', 'start_paragraph_id': 1, 'start_character': 0, 'end_paragraph_id': 1, 'end_character': 599, 'bleu_score': 0.706751840160576, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 2648213035679897882}, 'section': 'Section::::Abstract.'}]}]