Question: age 21 became the uniform legal drinking age across the us in
[{'answer': 'July 17 , 1984', 'provenance': [{'wikipedia_id': '1174672', 'title': 'National Minimum Drinking Age Act', 'start_paragraph_id': 1, 'start_character': 93, 'end_paragraph_id': 1, 'end_character': 107, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '1174672', 'title': 'National Minimum Drinking Age Act', 'start_paragraph_id': 1, 'start_character': 0, 'end_paragraph_id': 1, 'end_character': 417, 'bleu_score': 0.860927925537954, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 10741323695144423576}, 'section': 'Section::::Abstract.'}]}]