Question: which type of substance has the highest melting point
[{'answer': 'tungsten', 'provenance': [{'wikipedia_id': '40283', 'title': 'Melting point', 'start_paragraph_id': 5, 'start_character': 55, 'end_paragraph_id': 5, 'end_character': 63, 'bleu_score': 1.0, 'section': 'Section::::Examples.\n'}]}]