Question: who is johnny galecki on big bang theory
[{'answer': 'Dr. Leonard Hofstadter'}, {'provenance': [{'wikipedia_id': '2318278', 'title': 'Johnny Galecki', 'start_paragraph_id': 1, 'start_character': 0, 'end_paragraph_id': 1, 'end_character': 413, 'bleu_score': 0.722088039525544, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 1619151344865968525}, 'section': 'Section::::Abstract.'}]}]