We are all busy talking about and using the Internet ,but how many of us know about the history of the Internet? Many people are surprised when they find that the Internet was set up in the 1960s.At that time, computers were large and expensive. Computer networks didn' t work well .If one computer in the network broke down ,then the whole network stopped. So a new network system  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 be sent through another part.In this way the computer network system would keep on working all the time.At first,the Internet was only used by the government ,but,in the early 1970s, universities,hospitals and banks were allowed to use it too. However, computers were still expensive and the Internet was difficult to use.By the start of the 1990s,computers become cheaper and easier to use.Scientists had also developed software  that made "surfing " the Internet more convenient  . Today it is easy to get on-line and it is said that millions of people use the Internet every day. Sending e-mail is more and more popular among students. The Internet has now become one of the most important parts of people' s life. The Internet was widely used in the   _  .
1960s 1970s 1980s 1990s