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A．One second.B．Two years.C．One minute.D．A day.
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听力原文： A computer is a machine designed to perform. work mathematically and to store and select information that has been fed into it. It is run by either mechanical or electronic means. These machines can do a great deal of complicated work in a very short time. A large computer, for example, can add or subtract nine thousand times a second, multiply a thousand times a second, or divide five hundred times a second. Its percentage of error is about one in a billion digits. It has been estimated that human beings making calculations average about one mistake per two hundred digits.
The heart of an electronic computer lies in its vacuum tubes, or transistors. Its electronic circuits work a thousand times faster than the nerve cells in the human brain. A problem that might take a human being two years to solve can be solved by a computer in one minute, but in order to work properly, a computer must be given instructions--it must be programmed.
Computers can be designed for many specialized purposes--they can be used to prepare payrolls, guide airplane flights, direct traffic, even to play chess. Computers play an essential role in modern automation in many plants and factories throughout the world.
(33)
A．It can kill people.B．it can damage forests and plants.C．It can make it difficult to
听力原文： In 1968, the city of Philadelphia, Pennsylvania, had a problem. The city' s school system needed a new school building and teachers but did not have the money to pay for this multi million-dollar project.
City officials solved the problem in a unique way. They decided m use the many scientific and cultural institutions in the city as the classrooms. Experts who worked in the various institutions would be the teachers. About 100 institutions in Philadelphia -- public, private, and commercial -- helped the program.
The experiment in institutions in education, known as the Parkway Program, began in February 1969. John Bremer, an Englishman and an innovator in the field of education, planned the program and became its director.
The Program has grown in size from 142 to 500 high school students and is so popular that thousands of applicants are denied places each year. The program gives a freedom to high school education never known before. Besides basic courses required for a diploma -- languages, history, science -- students may choose from more than one hundred other courses. Any subject will be offered if an instructor can be found. Every group of 15 boys and girls belongs to a "tutorial group", led by a teacher and one assistant. Students in the Program say that school is no longer a place but an interesting activity.
(30)
The researchers believe they have demonstrated for the first time an ability among chimpanzees to transmit alternative technologies and alternative methods of using tools.
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