Question: when did the first pretty little liars air
[{'answer': 'June 8 , 2010', 'provenance': [{'wikipedia_id': '25857222', 'title': 'Pretty Little Liars', 'start_paragraph_id': 31, 'start_character': 35, 'end_paragraph_id': 31, 'end_character': 50, 'bleu_score': 1.0, 'section': 'Section::::Release.:Broadcast.\n'}]}]