Question: what does the cn stand for in the cn tower
[{'answer': 'Canadian National', 'provenance': [{'wikipedia_id': '6112', 'title': 'CN Tower', 'start_paragraph_id': 1, 'start_character': 211, 'end_paragraph_id': 1, 'end_character': 228, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}]