Question: who was the original voice of scooby doo
[{'answer': 'Don Messick', 'provenance': [{'wikipedia_id': '37287', 'title': 'Scooby-Doo', 'start_paragraph_id': 16, 'start_character': 188, 'end_paragraph_id': 16, 'end_character': 199, 'bleu_score': 1.0, 'section': 'Section::::Original television series run.:CBS years (1969–76).:"Scooby-Doo, Where Are You!".\n'}]}, {'provenance': [{'wikipedia_id': '37287', 'title': 'Scooby-Doo', 'start_paragraph_id': 76, 'start_character': 12, 'end_paragraph_id': 76, 'end_character': 792, 'bleu_score': 0.8212592039540281, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 8507572536116564809}, 'section': 'Section::::Cast.\n'}]}]