A backup program ( ).

单项选择题( ) are collections of two or more connected computers.

单项选择题We abbreviate Virtual Private Networks to ( ).

单项选择题A traditional private WAN can be ( ) to build and manage.

单项选择题To access the Web, users require a ( ) ,which is the software program used to access the World Wide Web.browser

单项选择题To protect data, you need to implement a data ( ) and recovery plan.above

单项选择题View shortcut menus by ( ) with the mouse.of the above

单项选择题Most RAM is( ).A and C

单项选择题A ( ) can be written to once. After that they can be read many times without deterioration but cannot be written on or erased.

单项选择题The two most common optical disks are CD and ( ).

单项选择题A(n) ( ) mouse emits and senses light to detect movement.