Question: which valves of the heart do not have chordae tendineae
[{'answer': 'semilunar valves', 'provenance': [{'wikipedia_id': '234803', 'title': 'Heart valve', 'start_paragraph_id': 25, 'start_character': 134, 'end_paragraph_id': 25, 'end_character': 150, 'bleu_score': 1.0, 'section': 'Section::::Structure.:Semilunar valves.\n'}]}, {'provenance': [{'wikipedia_id': '234803', 'title': 'Heart valve', 'start_paragraph_id': 25, 'start_character': 0, 'end_paragraph_id': 25, 'end_character': 537, 'bleu_score': 0.977397480575333, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 15924823807055132574}, 'section': 'Section::::Structure.:Semilunar valves.\n'}]}]