Question: the region that stretches between the black and caspian seas
[{'answer': 'The Caucasus Mountains', 'provenance': [{'wikipedia_id': '230497', 'title': 'Caucasus Mountains', 'start_paragraph_id': 1, 'start_character': 0, 'end_paragraph_id': 1, 'end_character': 22, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'answer': 'Caucasus Mountains', 'provenance': [{'wikipedia_id': '230497', 'title': 'Caucasus Mountains', 'start_paragraph_id': 0, 'start_character': 0, 'end_paragraph_id': 0, 'end_character': 18, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '230497', 'title': 'Caucasus Mountains', 'start_paragraph_id': 1, 'start_character': 0, 'end_paragraph_id': 1, 'end_character': 137, 'bleu_score': 0.5412047551441961, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 14246795312113435587}, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '230497', 'title': 'Caucasus Mountains', 'start_paragraph_id': 0, 'start_character': 0, 'end_paragraph_id': 0, 'end_character': 0, 'bleu_score': 1.0, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 14246795312113435587}, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '230497', 'title': 'Caucasus Mountains', 'section': 'Section::::Abstract.', 'start_paragraph_id': 1, 'end_paragraph_id': 1, 'meta': {'evidence_span': ['The Caucasus Mountains are a mountain system at the intersection of Europe and Asia. Stretching between the Black Sea and the Caspian Sea, it surrounds the eponymous Caucasus region and is home to Mount Elbrus, the highest peak in Europe.', 'The Caucasus Mountains are a mountain system at the intersection of Europe and Asia. Stretching between the Black Sea and the Caspian Sea, it surrounds the eponymous Caucasus region and is home to Mount Elbrus, the highest peak in Europe']}}]}, {'provenance': [{'wikipedia_id': '53579922', 'title': 'History of the western steppe', 'section': 'Section::::Geography.\n', 'start_paragraph_id': 3, 'end_paragraph_id': 3, 'meta': {'evidence_span': ['The southern boundary runs northeast and then east-southeast along the shore of the Black Sea, continues in the same direction along the north side of the Caucasus Mountains, meets the Caspian Sea and follows its western shore north.', 'western shore north. Between the north end of the Caspian to the Urals is open grassland that connects the area to the central steppe. The Sea of Azov projects northeast, turning the Black Sea-Caspian Steppe into a kind of peninsula. The western part is sometimes called the Kuban region from the Kuban River that drains the Caucasus northwest. The Crimean peninsula extends into the Black Sea and was a link from the steppe to the Byzantine and Turkish empires. In the far west, the Hungarian plain is an island of grassland separated from the main steppe by the mountains of Transylvania. Most of the area is suitable for agriculture except for the semi-desert west and north of the Caspian. North-south trade routes were along the Volga River and Dnieper River. Between them the Don River']}}]}]