The analyst г)uses a computer for solving problems, while the computer system architect б)designs computers. 
а)controls б)designs в)requires г)uses

Programs and data to be processed must be in the a) internal memory. 
a) internal; б) external; в) secondary 

The read out command is passed from the в) storage  register to the a) instruction register.
a) instruction; б) address; в) storage 

The four б) circuits are used to perform basic operations in a computer.
a) basics; б) circuits; в) equipment

The function of memory is to store a) not only the original data but also the partial results.
a) not only…. but also; б) either…or; в) no sooner … than

The в) central processor includes the control and arithmetic-logical units.
a) flip-flop; б) digital computer; в) central processor

Input-output devices allow the computer to в) communicate with its external environment.
a) compute; б) command; в) communicate

An I/O interface is a special б) processor that converts input data to the internal codes.
a) register; б) processor; в) plotter

Мне кажется что все три варианта правильные a) high-speed; б) medium-speed; в) low-speed devices allow the computer to communicate with its external environment.

a) high-speed; б) medium-speed; в) low-speed