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.

单项选择题A location in RAM memory is accessed by its( )

单项选择题Accessing data from a floppy disk is called( )dat

单项选择题The( )led to the invention of personal computers,or microcomputers.

单项选择题The fourth generation computers can be characterized by both the jump to monolithic integrated circuits and the invention of( ).

单项选择题Most electronic devices today use some form. of( )placed on printed circuit boards.circuits

单项选择题The common input devices are the ( ) and the ( ).

单项选择题A computer must include three of following.Which one is not necessary?

单项选择题RAM is a( )storage.