Question: where are the cannula most commonly placed for cardiopulmonary bypass procedures
[{'answer': 'ascending aorta', 'provenance': [{'wikipedia_id': '261827', 'title': 'Cardiopulmonary bypass', 'start_paragraph_id': 6, 'start_character': 630, 'end_paragraph_id': 6, 'end_character': 645, 'bleu_score': 1.0, 'section': 'Section::::Uses.\n'}]}, {'provenance': [{'wikipedia_id': '261827', 'title': 'Cardiopulmonary bypass', 'start_paragraph_id': 6, 'start_character': 0, 'end_paragraph_id': 6, 'end_character': 1208, 'bleu_score': 0.9533086364313991, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 11851479299796355686}, 'section': 'Section::::Uses.\n'}]}]