Question: do wind turbines produce ac or dc power
[{'answer': 'AC', 'provenance': [{'wikipedia_id': '8309537', 'title': 'Wind turbine design', 'start_paragraph_id': 53, 'start_character': 499, 'end_paragraph_id': 53, 'end_character': 501, 'bleu_score': 1.0, 'section': 'Section::::Nacelle.:Generator.\n'}]}, {'provenance': [{'wikipedia_id': '8309537', 'title': 'Wind turbine design', 'start_paragraph_id': 53, 'start_character': 0, 'end_paragraph_id': 53, 'end_character': 822, 'bleu_score': 0.9845548242372031, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 14084916418379193825}, 'section': 'Section::::Nacelle.:Generator.\n'}]}]