Question: which river separates the bronx in new york city from manhattan island
[{'answer': 'Harlem River', 'provenance': [{'wikipedia_id': '3338', 'title': 'The Bronx', 'start_paragraph_id': 1, 'start_character': 179, 'end_paragraph_id': 1, 'end_character': 191, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'answer': 'the Harlem River', 'provenance': [{'wikipedia_id': '3338', 'title': 'The Bronx', 'start_paragraph_id': 1, 'start_character': 175, 'end_paragraph_id': 1, 'end_character': 191, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '3338', 'title': 'The Bronx', 'start_paragraph_id': 1, 'start_character': 0, 'end_paragraph_id': 1, 'end_character': 366, 'bleu_score': 0.8565799162656831, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 12816108900034832235}, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '287802', 'title': 'Harlem River', 'section': 'Section::::Geology and geography.\n', 'start_paragraph_id': 4, 'end_paragraph_id': 4, 'meta': {'evidence_span': ['The Harlem River forms a part of the Hudson estuary system, serving as a narrow strait that divides the island of Manhattan from the Bronx', 'The Harlem River forms a part of the Hudson estuary system, serving as a narrow strait that divides the island of Manhattan from the Bronx. Approximately 18,000 years ago the Laurentide ice sheet receded northward across the continent leaving behind a large escarpment creating the modern day Hudson River. About 6,000 years ago the Hudson River emptied into the ancient Atlantic Ocean, depositing sediments over the bedrock; this resulted in the formation of the Hudson River estuary, which is the water and land at the mouth of the river that contains a mixture of salt and freshwater, including the Harlem River.', 'The Harlem River forms a part of the Hudson estuary system, serving as a narrow strait that divides the island of Manhattan from the Bronx.']}}]}, {'provenance': [{'wikipedia_id': '3338', 'title': 'The Bronx', 'section': 'Section::::Abstract.', 'start_paragraph_id': 1, 'end_paragraph_id': 1, 'meta': {'evidence_span': ['The Bronx is the northernmost of the five boroughs of New York City, in the U.S. state of New York. It is south of Westchester County; northeast and east of Manhattan, across the Harlem River; and north of Queens, across the East River. Since 1914, the borough has had the same boundaries as Bronx County, the third-most densely populated county in the United States.', 'The Bronx is the northernmost of the five boroughs of New York City, in the U.S. state of New York. It is south of Westchester County; northeast and east of Manhattan, across the Harlem River; and north of Queens, across the East River. Since 1914, the borough has had the same boundaries as Bronx County, the third-most densely populated county in the United States.']}}]}]