根据材料回答下列各题： 'We are not about to enter the Information Age, but instead are rather well into it.' Presentpredictions are that by 1990, about thirty million jobs in the United States, or about thirty percentof the job market, will be computer-related. In 1980, only twenty-one percent of all American highschools owned one or two computers for student use. In the fall of 1985, a new study showed thathalf of United States secondary schools have fif or more computers for student use. And noweducational experts, administrators, and even the general public are demanding that all students be-come 'computer-literate'. By the year 2000 knowledge of computers will be necessary in overeighty percent of all occupations. Soon those people not educated in computer use will be comparedto those who are print-illiterate today. What is 'computer literacy'? The term itself seems to imply some degree of 'knowing' aboutcomputers, but knowing what? The present opinion seems to be that this should include a generalknowledge of what computers are, plus a little of their history and something of how they operate.Therefore, it is important that educators everywhere take a careful look not only at what is being done, but also at what should be done in the field of computer education. Today most s are able to use a motor car without the slightest knowledge of how the internal combustion engine(内燃机) works. We effectively use all types of electrical equipment without being able to tell their histo-ries to explain how they work. Business people for years have made good use of typewriters and adding machines, yet fewhave ever known how to repair them. Why, then, attempt to teach computers by teaching how orwhy they work? Rather, we first must fix our mind on teaching the effective use of the computer as the tool is.'Knowing how to use a computer is what’s going to be important. We don’t talk about ‘au-tomobile literacy'. We just get in our cars and drive them.' In 1990, the number of jobs having nothing to do with computers in the United States will be reduced to_______