Question: what was the purpose of the wall of jericho
[{'answer': 'defensive or flood protection', 'provenance': [{'wikipedia_id': '8317931', 'title': 'Wall of Jericho', 'start_paragraph_id': 1, 'start_character': 57, 'end_paragraph_id': 1, 'end_character': 86, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '8317931', 'title': 'Wall of Jericho', 'start_paragraph_id': 1, 'start_character': 0, 'end_paragraph_id': 1, 'end_character': 416, 'bleu_score': 0.936655266249045, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 12156697461243917047}, 'section': 'Section::::Abstract.'}]}]