Lesson 51 PART A
Predicting the future
Predicting the future is notoriously difficult.Who could have imagined, in the mid 1970s,for example,that by the end of the 20th century,computers would be as common in people's homes as TV sets? In the 1970s,computers were common enough ,but only in big business,government departments,and large organizations.These were the so-called mainframe machines.(1)_______________________. Though these large machines still exist,many of their functions have been taken over by small powerful personal computers,commonly known as PCs.
In 1975,a primitive machine called the Altair,was launched in the USA.It can properly be described as the first 'home computer' and it pointed the way to the future.This was followed,at the end of the 1970s,by a machine called an Apple.In the early 1980s,the computer giant,IBM produced the world's first Personal Computer.This ran on an 'operating system' called DOS,produced by a then small company named Microsoft.The IBM Personal Computer was widely copied.(2)_______________________.
发表于 2011-11-16 10:16
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