Question: who plays wicked witch on once upon a time
[{'answer': 'Rebecca Leigh Mader', 'provenance': [{'wikipedia_id': '5645119', 'title': 'Rebecca Mader', 'start_paragraph_id': 1, 'start_character': 0, 'end_paragraph_id': 1, 'end_character': 19, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '5645119', 'title': 'Rebecca Mader', 'start_paragraph_id': 1, 'start_character': 0, 'end_paragraph_id': 1, 'end_character': 205, 'bleu_score': 0.950578622812921, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 167333060454800866}, 'section': 'Section::::Abstract.'}]}]