Question: what kind of bridge is the mackinac bridge
[{'answer': 'suspension bridge', 'provenance': [{'wikipedia_id': '20321', 'title': 'Mackinac Bridge', 'start_paragraph_id': 1, 'start_character': 29, 'end_paragraph_id': 1, 'end_character': 46, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '20321', 'title': 'Mackinac Bridge', 'start_paragraph_id': 1, 'start_character': 0, 'end_paragraph_id': 1, 'end_character': 663, 'bleu_score': 0.8394887562902921, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 9764067235014324555}, 'section': 'Section::::Abstract.'}]}]