整句
简述保费的计算原则主要有哪些？
额法是以产品的（）成本为基础，加、减（）差异和（）差异计算产品实际成本的一种方法。
One of your customers wishes to use the NAS to perform DHCP functions and does not currently have a Layer 3 gateway in its production network. Which gateway mode is appropriate for this customer?（） ["Virtual Gateway","Real-IP Gateway","NAT Gateway","IP-IP Gateway"]
中倍数泡沫灭火系统中，局部应用系统主要适用于（）。 ["四周不完全封闭的A类火灾场所","限定位置的流散B类火灾场所","固定位置面积不大于100m2的流淌B类火灾场所","较小火灾场所","丙类固定顶与内浮顶油罐"]
成语和惯用语有哪些区别？
