In the communications industry, what are the features and benefits of using the layered OSI model?（）
A. It encourages industry standardization by defining what functions occur at each layer of the model.
B. It necessitates changes in functionality in one layer to other layers.
C. It enables equipment efficiency from different vendors to use the same electronic components.
D. It divides the network communication process into smaller and simpler components, thus aiding component development, design, and troubleshooting.
E. It supports the evolution of multiple competing standards, and thus enhances business equipment manufacturing opportunities.
患者男，22岁。诉全身疼痛伴恶心、腹痛1天前来就诊。患者表现烦躁不安，心率加快、流涕流泪、震颤、恶心、呕吐。体查发现患者腹部平软，无压痛反跳痛，双上肢静脉有多处陈旧性针痕。神经系统检查无异常。大便常规、血常规、腹部B超均未见明显异常。患者否认有药物滥用史，但乞求医生注射哌替啶止痛。为了做出正确的诊断，对该患者最需要做的是（）
A. 再次询问用药史
B. 脑脊液检查
C. 给予哌替啶注射
D. 给予止呕药物
E. 尿毒品检测
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