Question: what is the political system in the usa
[{'answer': 'federal republic', 'provenance': [{'wikipedia_id': '32021', 'title': 'Politics of the United States', 'start_paragraph_id': 1, 'start_character': 23, 'end_paragraph_id': 1, 'end_character': 39, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '32021', 'title': 'Politics of the United States', 'start_paragraph_id': 1, 'start_character': 0, 'end_paragraph_id': 1, 'end_character': 241, 'bleu_score': 0.80846720196545, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 1302958371425454051}, 'section': 'Section::::Abstract.'}]}]