Question: which layer of the alimentary canal produces mucous
[{'answer': 'mucous membrane', 'provenance': [{'wikipedia_id': '69447', 'title': 'Mucous membrane', 'start_paragraph_id': 1, 'start_character': 2, 'end_paragraph_id': 1, 'end_character': 17, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '69447', 'title': 'Mucous membrane', 'start_paragraph_id': 1, 'start_character': 0, 'end_paragraph_id': 1, 'end_character': 622, 'bleu_score': 0.9666465443060471, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 15128185499601614866}, 'section': 'Section::::Abstract.'}]}]