Question: when did us start fighting in europe ww2
[{'answer': '11 December 1941'}, {'provenance': [{'wikipedia_id': '4653534', 'title': 'Military history of the United States during World War II', 'start_paragraph_id': 22, 'start_character': 0, 'end_paragraph_id': 22, 'end_character': 123, 'bleu_score': 0.5770537815094741, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 12208347040088861452}, 'section': 'Section::::European and North African Theaters.\n'}]}]