Question: what structure separates the right atria from the left atria
[{'answer': 'the tricuspid valve', 'provenance': [{'wikipedia_id': '1317242', 'title': 'Atrium (heart)', 'start_paragraph_id': 4, 'start_character': 390, 'end_paragraph_id': 4, 'end_character': 409, 'bleu_score': 1.0, 'section': 'Section::::Structure.\n'}]}, {'provenance': [{'wikipedia_id': '1317242', 'title': 'Atrium (heart)', 'start_paragraph_id': 4, 'start_character': 0, 'end_paragraph_id': 4, 'end_character': 695, 'bleu_score': 0.982060959997838, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 2301030951628142669}, 'section': 'Section::::Structure.\n'}]}]