Question: when did the us acquire the us virgin islands
[{'answer': '1917', 'provenance': [{'wikipedia_id': '2748206', 'title': 'History of the United States Virgin Islands', 'start_paragraph_id': 7, 'start_character': 67, 'end_paragraph_id': 7, 'end_character': 71, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '2748206', 'title': 'History of the United States Virgin Islands', 'start_paragraph_id': 28, 'start_character': 0, 'end_paragraph_id': 28, 'end_character': 868, 'bleu_score': 0.9369318767987571, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 5354061109121428680}, 'section': 'Section::::American rule.\n'}]}]