投保施工人员意外伤害险，施工单位与保险公司双方应根据各类风险因素商定保险费率，实行（）。 ["差别费率和最低费率","浮动费率和标准费率","标准费率和最低费率","差别费率和浮动费率"]
韵律是指事物在运动过程中其相同因素有规律地重复的连续形式。
压溶作用
Which two of these are correct regarding the recommended practice for distribution layer designbased on the following configuration？（） [" use a Layer 2 link between distribution switches"," use a Layer 3 link between distribution switches"," use a redundant link to the core"," use a Layer 3 link between distribution switches with route summarizatio"]
钢丝绳的安全检查内容有哪些？
混床再生液（碱度）为什么要加热？
