We are all busy talking about and using the Internet, but how many of us know the history of the Internet?
Many people are surprised when they find that the Internet was set up（建立） in the 1960s. At that time, computers were large and expensive. Computer networks（网络） didn’t work well. If one computer in the network broke down, then the whole network stopped. So a new network system（系统） had to be set up. It should be good enough to be used by many different computers. If part of the network was not working, information could still be sent through another part. In this way the computer network system would keep on working all the time.
