Question: who designed the welcome to las vegas sign
[{'answer': 'Betty Willis', 'provenance': [{'wikipedia_id': '1710951', 'title': 'Welcome to Fabulous Las Vegas sign', 'start_paragraph_id': 1, 'start_character': 147, 'end_paragraph_id': 1, 'end_character': 159, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '1710951', 'title': 'Welcome to Fabulous Las Vegas sign', 'start_paragraph_id': 1, 'start_character': 0, 'end_paragraph_id': 1, 'end_character': 243, 'bleu_score': 0.9569637990759251, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 16036644356662334989}, 'section': 'Section::::Abstract.'}]}]