In April 1995, a young Chinese chemistry student at Beijing University lay dying in a Beijing hospital. She was in a coma, and a

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问题    In April 1995, a young Chinese chemistry student at Beijing University lay dying in a Beijing hospital. She was in a coma, and although her doctors had performed numerous tests, they could not discover what was killing her. In desperation, a student friend posted an SOS describing her symptoms to several medical bulletin boards and mailing lists on the Internet. Around the world, doctors who regularly checked these electronic bulletin boards and lists responded immediately.
   In Washington D. C. , Do, John Aldis, a physician with the U.S. Department of State, saw the message from China. Using the Internet, he forwarded the message to colleagues in America. Soon an international group of doctors joined the e- mail discussion. A diagnosis emerged -- the woman might have been poisoned with thallium, a metal resembling lead. A Beijing laboratory confirmed this diagnosis -- the thallium concentration in her body was an much as 1,000 times normal. More e-mail communication followed, as treatment was suggested and then adjusted. The woman slowly began to recover. Well over a year later, the international medical community was still keeping tabs on her condition through the electronic medium that saved her life.
   It’s 11: 30 p. m. , you’re is San Francisco on business, and you want to check for messages at your office in Virginia. First you dial in and get your voice mail. Next you plug your portable computer into the hotel-room telephone jack, hit a few keys, and pick up e-mall from a potential client in South Africa, your sister in London, and a business associate in Detroit. Before writing your response, you do a quick bit of search on the Internet, tracking down the name of the online news group you had mentioned to the man in Detroit and the title of a book you wanted to recommend to your sister. A few more keystrokes and in moments your electronic letters have reached London and Detroit. Then, knowing that the time difference means the next workday has begun in South Africa, you call there without a second thought.
   These stories reflect society’s increasing reliance on system of global communication that can link you equally easily with someone in the next town or halfway around the world. The expanded telephone-line capacity that has allowed the growth of these forms of communication is a recent phenomenon. The United States has enjoyed domestic telephone service for more than a century, but overseas telephone calls were difficult until relatively recently. For a number of years after World War Ⅱ, calls to Europe or Asia retied on short-wave radio signals. It sometimes took an operator hours to set up a 3- minute call , and if you got through, the connection was often noisy.
   In 1956, the first transatlantic copper wire cable allowed simultaneous transmission of 36 telephone conversations -- a cause for celebration then, a small number today. Other cables followed; by the early 1960s, overseas telephone calls had reached 5 million per year. Then came satellite communication in the middle 1960s, and by 1980, the telephone system carried some 200 million overseas calls per year. But as demands on the telecommunication system continued to increase, the limitations of current technology became apparent. Then, in 1988, the first transatlantic fiber-optic cable was laid, and the "information superhighway" was on its way to becoming reality.
   Optical fibers form the backbone of the global telecommunication system stronger, length for length, than steel -- were designed to carry the vast amounts of data that can be transmitted via a relatively new form of light-tightly focused laser. Together, lasers and optical fibers have dramatically increased the capacity of the international telephone system. A typical fiber-optic cable made up of 100 or more such fibers can carry more than 40,000 voice channels. With equally striking improvements in computing, the new communication technology has fueled the exponential growth of the phenomenon known as the Internet.
Which of the following best expresses the main idea of the passage?

选项 A、It is optical fibers and lasers that have made the information superhighway possible.
B、People can communicate with each other more quickly now on the Internet.
C、It has taken quite a long time for the Intern to come into existence.
D、If one is seriously ill, he can always get help via the modem communication system.

答案A

解析 该题问:下列的哪一句最能表达本文的主要意思? A项意为“可视纤维与激光使得信息高速公路成为可能”,本文的潜在标题就是Modern Communication:The Laser and Fiber-Optic Revolution,毫无疑问A项为正确选项。B项意为“人们可以在网上互相交流得更快”,这并不是作者要说明的。C项意为“互联网成为现实花了很长一段时间”,这也并不是作者要说明的。D项意为“如果一个人病得很严重,他可以经常通过现代通信系统得到帮助”,这只是现代通信系统的优处之一,所以D项不正确。
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