分析短语的结构层次，一般采取（）的分析步聚进行分析。
教育实验设计实施的核心内容是（） ["变量分解","变量预测","变量假设","变量控制"]
In a collapsed core design, which two benefits are provided by a second-generation Cisco MDS director（） [" a higher fan-out ratio"," fully redundant switches"," 100 percent port efficiency","allI S Lscontained with inasingle chass is","higher latency and through put than acore-edged esign switch"]
下列哪一项不是人员定向分析的内容（） ["政治素质分析","体力、体质要求分析","创造性要求分析","知识水平要求分析"]
交通事故已经成为我国危害人身安全的重要因素之一。公安部门规定，坐在客车前排的驾驶员和乘客都必须在胸前系上安全带，为什么？
沉积岩
