Question: what event began the second front in world war ii
[{'answer': 'the Allied landings in Normandy', 'provenance': [{'wikipedia_id': '519516', 'title': 'Western Front (World War II)', 'start_paragraph_id': 1, 'start_character': 799, 'end_paragraph_id': 1, 'end_character': 830, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '519516', 'title': 'Western Front (World War II)', 'start_paragraph_id': 1, 'start_character': 0, 'end_paragraph_id': 1, 'end_character': 884, 'bleu_score': 0.9860618656782161, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 10716461747990910078}, 'section': 'Section::::Abstract.'}]}]