Passage D
We are all busy taking 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 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, computer network system would keep on working all the time.At first the Internet was only used by the government (政府). But in the early 1970s, universities, hospitals and banks were allowed to use it, too. However, computers were still very expensive and the Internet was difficult to use. By the start of the 1990s, computers became 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 millions of people use the Internet every day. Sending e-mails is more and more popular among students.The Internet has now become one of the most important parts of people's life.
1. The Internet has a history of more than _________ years.
Afifty
Bten
Cforty
Dtwenty
