Question: who replaced johnny carson on the tonight show
[{'answer': 'Jay Leno', 'provenance': [{'wikipedia_id': '99961', 'title': 'The Tonight Show', 'start_paragraph_id': 1, 'start_character': 374, 'end_paragraph_id': 1, 'end_character': 382, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}]