Question: who is the actress who plays alex on big bang theory
[{'answer': 'Margo Cathleen Harshman', 'provenance': [{'wikipedia_id': '1767258', 'title': 'Margo Harshman', 'start_paragraph_id': 1, 'start_character': 0, 'end_paragraph_id': 1, 'end_character': 23, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '1767258', 'title': 'Margo Harshman', 'start_paragraph_id': 1, 'start_character': 0, 'end_paragraph_id': 1, 'end_character': 219, 'bleu_score': 0.526455893026187, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 2863146831013085991}, 'section': 'Section::::Abstract.'}]}]