Question: what does the pt stand for in pt boat
[{'answer': 'Patrol Torpedo', 'provenance': [{'wikipedia_id': '53165', 'title': 'PT boat', 'start_paragraph_id': 1, 'start_character': 22, 'end_paragraph_id': 1, 'end_character': 36, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '53165', 'title': 'PT boat', 'start_paragraph_id': 1, 'start_character': 0, 'end_paragraph_id': 1, 'end_character': 399, 'bleu_score': 0.930807147807393, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 1808205341481620094}, 'section': 'Section::::Abstract.'}]}]