B4

The first generation of computers was developed during 1943 - 1958. It used vacuum tubes as memory device and was therefore very large. Those computers were very expensive and consumed a lot of electrical power.
(первый)

 ONE

B5

The second generation was developed during 1959 - 1965. The invention of the transistor by three scientists of Bell Telephone Laboratories in 1947 greatly changed the development of computers.
(второй)

 TWO

B6

The third generation computers were developed during 1966 - 1973. These computers used integrated circuits. They were small, efficient and reliable. Monitors and keyboards were introduced for input and output of data.
(третий)

 THREE

B7

The fourth generation computers were developed during 1974 - 1990. This generation of computer is presently in use. Its sizes were reduced to desktop and laptop computer. These computers are highly reliable and accurate.
(четвёртый)

 FOUR

B8

The computers having artificial intelligence and high processing capacity undergoing on the development stage from 1990 are said to be the fifth generation computers. The goal of fifth generation computers is to develop machines that will be able to think and take decisions.
(1. пятый 2. пятый)

 FIVE

 FIVE