The four basic units of simplified computer: the input unit, central processing unit, memory unit, and output unit.
The central processing unit (CPU) is the heart of the computer system. It is responsible for performing all arithmetic operations and logic decisions initiated by the program.
The memory unit of the computer is used to store information such as numbers, names, and addresses.In computer system, memory is divided into two different sections, known as main storage and auxiliary storage. They are also sometimes called internal memory and external memory respectively.
The input and output units are the means by which the CPU communicates with the outside world.The input unit is used to input information and commands to the CPU for processing.After processing, the information that results must be output.This output of data from the system is performed under control of the output unit.
Based on the paragraph above,(   ) is the most important unit of the computer system, memory is regarded as (   )disparate kinds,（  ） connects computer and human.