Question: how does the oral cavity help the digestive system
[{'answer': 'produces a lubricating mucus', 'provenance': [{'wikipedia_id': '42193218', 'title': 'Human digestive system', 'start_paragraph_id': 13, 'start_character': 455, 'end_paragraph_id': 13, 'end_character': 483, 'bleu_score': 1.0, 'section': 'Section::::Components.:Mouth.\n'}]}, {'provenance': [{'wikipedia_id': '42193218', 'title': 'Human digestive system', 'start_paragraph_id': 13, 'start_character': 0, 'end_paragraph_id': 13, 'end_character': 1206, 'bleu_score': 0.983005613198717, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 16342310561896884937}, 'section': 'Section::::Components.:Mouth.\n'}]}]