messages.content: 请提取出句子中的属性词、正向情感(情感词)、负向情感(情感词)、中性情感(情感词)并给出位置，以[[{"type":词1类别, "span":词1名称,"offset":词1位置}], [{"type":词2类别, "span":词2名称,"offset":词2位置}], ...]的格式回答。
messages.role: system
messages.content: 8开人美版的，开本大，清晰，看起来真不错！
messages.role: user
messages.content: [[{"type": "属性词", "span": "开本", "offset": [7, 9]}, {"type": "正向情感(情感词)", "span": "大", "offset": [9, 10]}], [{"type": "属性词", "span": "开本", "offset": [7, 9]}, {"type": "正向情感(情感词)", "span": "清晰", "offset": [11, 13]}], [{"type": "属性词", "span": "看起来", "offset": [14, 17]}, {"type": "正向情感(情感词)", "span": "真不错", "offset": [17, 20]}]]
messages.role: assistant