what’s IOS command ， you can see the output as below ：
常用的动态评价指标有哪些
为什么发电机的出线电压标准是400V而不是380V？
寿命周期成本
Refer to the exhibit. Which statement is true?（） ["The Fa0\/11 role confirms that SwitchA is the root bridge for VLAN 20.","VLAN 20 is running the Per VLAN Spanning Tree Protocol.","The MAC address of the root bridge is 0017.596d.1580.","SwitchA is not the root bridge, because not all of the interface roles are designated."]
为什么我们要求客户安装机组时，排烟管要向下倾斜5-10度？
