单项选择题 Which is the correct fallback sequence for loading the Cisco IOS?（）

多项选择题 You are a trainee technician at TestKing, Inc. Your instructor tells you to backup an IOS image of a Cisco device to a Windows 2003 server on the network.What should you do first?（）

单项选择题 You wish to upgrade the IOS of a router without removing the image currently installed.What command will display the amount of memory that is being used by the current IOS image and whether there is enough room available to hold both the current and new images?（）