Question: when are both valves closed during cardiac cycle
[{'answer': 'Isovolumic contraction', 'provenance': [{'wikipedia_id': '2525843', 'title': 'Cardiac cycle', 'start_paragraph_id': 9, 'start_character': 101, 'end_paragraph_id': 9, 'end_character': 123, 'bleu_score': 1.0, 'section': 'Section::::The cardiac cycle and Wiggers diagram.\n'}]}]