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  3. In recent years scientists have found that the laser has a wide variety of applications, making it one of the most important inv

In recent years scientists have found that the laser has a wide variety of applications, making it one of the most important inv

admin2009-05-04  73
问题     In recent years scientists have found that the laser has a wide variety of applications, making it one of the most important inventions for improving our quality of life.
    One important field in which the laser has many applications is communications. Scientists have found that the laser beam can transmit human voices; as a result, telephone companies are now using laser light signals to transmit telephone calls through extremely small cables that are capable of carrying many more transmissions than the standard telephone cables. An additional advantage is that these systems using the laser light signals are also able to transmit video telephone conversations.
    Another, perhaps less-known, field in which lasers are helping improve the quality of life is metrology—the science of measurement. The extremely straight, narrow laser beam can be used to put the parts of a structure being built into the correct position to each other. The laser beam has also been used to measure remote distances, for example, the precise distance from the Earth to the Moon.  And finally, the laser can be used to measure the drifts of the Earth’s plates. This measurement, along with other data, can help in the pre-diction of the earthquakes.
    Probably the most vital application of the laser is in the field of medicine. Scientists have developed a laser kniffe that surgeons can use for operations. These knives are now used widely because they cut sharply and because the beam seals off the blood vessels that it cuts, thus reducing blood loss considerably.
    When Dr. Theodore got the first laser to work in July 1960, what uses it would have were unknown; in fact he called it a multimillion-dollar "solution in search of a problem". As we have seen, the uses of the laser are numerous. It is being used in the fields of medicine, communications, and metrology. There are many, many more applications, such as in the areas of defense and space travel.  What should be apparent by now is that there are many problems the laser is helping to solve, and that the laser, if used wisely, can be a life-saving device.
The best title of the text might be______.
选项 A、The Laser: A Scientific and Technological Wonder
B、The Laser: A Powerful Tool for Communications
C、The Laser: A Solution to Life-Saving Problems
D、The Laser: A Multimillion Dollar Invention
答案A
解析 主旨题。从文章的整体意思来看，作者在这篇文章里面描述了激光作为科技发展的产物在通讯、医药等领域起到巨大作用。可以说激光是现代科技的一个奇迹。其他概括不够全面，或有失偏颇。故正确的答案为A。
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