Question: what river is the western border of the state illinois
[{'answer': 'the Mississippi River', 'provenance': [{'wikipedia_id': '2812707', 'title': 'Geography of Illinois', 'start_paragraph_id': 1, 'start_character': 302, 'end_paragraph_id': 1, 'end_character': 323, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '2812707', 'title': 'Geography of Illinois', 'start_paragraph_id': 1, 'start_character': 0, 'end_paragraph_id': 1, 'end_character': 714, 'bleu_score': 0.9428522379964921, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 9612609340867668726}, 'section': 'Section::::Abstract.'}]}]