Question: the lines that join points of equal elevation above the mean sea level are known by what name
[{'answer': 'contour line', 'provenance': [{'wikipedia_id': '650086', 'title': 'Contour line', 'start_paragraph_id': 1, 'start_character': 2, 'end_paragraph_id': 1, 'end_character': 14, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '650086', 'title': 'Contour line', 'start_paragraph_id': 1, 'start_character': 0, 'end_paragraph_id': 1, 'end_character': 719, 'bleu_score': 0.903293220297892, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 12619051249951003194}, 'section': 'Section::::Abstract.'}]}]