Question: when did the us reopen its diplomatic mission in cuba
[{'answer': 'July 20 , 2015', 'provenance': [{'wikipedia_id': '43084725', 'title': 'Embassy of the United States, Havana', 'start_paragraph_id': 8, 'start_character': 127, 'end_paragraph_id': 8, 'end_character': 141, 'bleu_score': 1.0, 'section': 'Section::::History.\n'}]}, {'provenance': [{'wikipedia_id': '43084725', 'title': 'Embassy of the United States, Havana', 'start_paragraph_id': 1, 'start_character': 0, 'end_paragraph_id': 1, 'end_character': 636, 'bleu_score': 0.979896933041101, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 12678420418302938235}, 'section': 'Section::::Abstract.'}]}]