Question: what is the fluid-filled space behind the oval window
[{'answer': 'cochlear duct', 'provenance': [{'wikipedia_id': '134971', 'title': 'Cochlea', 'start_paragraph_id': 17, 'start_character': 141, 'end_paragraph_id': 17, 'end_character': 154, 'bleu_score': 1.0, 'section': 'Section::::Structure.:Microanatomy.\n'}]}, {'provenance': [{'wikipedia_id': '134971', 'title': 'Cochlea', 'start_paragraph_id': 17, 'start_character': 0, 'end_paragraph_id': 17, 'end_character': 401, 'bleu_score': 0.9679895851501501, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 13117069544696953949}, 'section': 'Section::::Structure.:Microanatomy.\n'}]}]