简述密码体制的原则：
There are many reasons why customers lack sufficient security measures on the network. Which two reasons for insufficient security are typical of the customers today?（） the use of hosted email services eliminating the need for local security。 the perceived costs of security solutions。 the lack of risk analysis。 the lack of threats to their network。 the belief that free security tools are sufficient。 the desire to avoid unnecessary technologie。
When assigning a standalone access point a non-root role， which two parameters， other than role in the radio network settings， must be configured on the ssid manager page？（） force infrastructure devices to associate only to this ssid。 set infrastructure ssid。 multiple bssid。 set data beacon rate。 enable ip redirection on this ssid。
简述软骨鱼纲的主要特征。
货币经纪人
易熔合金塞式泄压装置的缺点为（）。
