Question: which civilizations developed in the fertile valley between the tigris and euphrates rivers
[{'answer': 'Mesopotamia', 'provenance': [{'wikipedia_id': '9031507', 'title': 'River valley civilization', 'start_paragraph_id': 1, 'start_character': 597, 'end_paragraph_id': 1, 'end_character': 608, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '9031507', 'title': 'River valley civilization', 'start_paragraph_id': 3, 'start_character': 0, 'end_paragraph_id': 3, 'end_character': 585, 'bleu_score': 0.854638031844496, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 8290874576996086481}, 'section': 'Section::::History.\n'}]}]