Question: who is the current speaker of the house of commons
[{'answer': 'John Bercow', 'provenance': [{'wikipedia_id': '332849', 'title': 'Speaker of the House of Commons (United Kingdom)', 'start_paragraph_id': 1, 'start_character': 169, 'end_paragraph_id': 1, 'end_character': 180, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}]