Independent work on the subject of English by alijonov ibratjon

Comprehension check

Exercise 2. Replace the passages in their logical order. (ёзма, письменно)

_____3________When the protocols were formed, much of the software and services that make up the Internet appeared. The basic services for remote connectivity, file transfer, and electronic mail were introduced in the mid and late seventies. The Usenet news system appeared in 1981 and the World Wide Web information system in 1989.

___1________The Internet of today is only one third a research and educational network because of universities and institutes connected to it. However, commercial communications have taken over the majority of Internet traffic.

____4______In 1990, the ARPANET had had many other networks connected to it. Later, its role as a network backbone was taken over by the NSFNET funded by the National Science Foundation. The networking companies and organizations which provided the data connections to all the Internet hosts continued in their goal of providing easy global network access.

____2________The Internet developed from the project initiated by the US Department of Defense – Advanced Research Projects Agency (ARPA). The ARPANET, as it was then called, was designed to be a non-reliable network service for computer communications over wide area. In 1973 and 1974, a standard networking protocol, a communications protocol for exchanging data between computers on a network, emerged from the various research and educational programs involved in this project. This became known as TCP/IP or the IP suite of protocols.

___5______These protocols enabled ARPANET computers to communicate irrespective of their computer operating system or their computer hardware. We call such protocols heterogeneous. UNIX operating system was developed in the same era and TCP/IP became almost synonymous with the UNIX which was spread throughout the many educational institutions around the US for a low cost. Multi-user systems such as UNIX soon became the most popular method of accessing the Internet.