Question: who serves as president of the united states senate
[{'answer': 'the Vice President', 'provenance': [{'wikipedia_id': '24909346', 'title': 'United States Senate', 'start_paragraph_id': 4, 'start_character': 298, 'end_paragraph_id': 4, 'end_character': 316, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '24909346', 'title': 'United States Senate', 'start_paragraph_id': 58, 'start_character': 0, 'end_paragraph_id': 58, 'end_character': 918, 'bleu_score': 0.9876155018005031, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 14791178299033618017}, 'section': 'Section::::Officers.:Presiding over the Senate.\n'}]}]