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公共英语三级阅读文章

时间:2020-08-17 12:08:55 三级 我要投稿

2017公共英语三级阅读文章

  对于公共英语三级,考生如果想取得比较好的成绩还是需要多看多练习的。下面,就为大家送上2017公共英语三级阅读文章三篇。

2017公共英语三级阅读文章

  2017公共英语三级阅读文章一

  The modern age is an age of electricity. People are so used to electric lights, radio, televisions, and telephones that it is hard to imagine what life would be like without them. When there is a power failure, people grope about in flickering candlelight, cars hesitate in the streets because there are no traffic lights to guide them, and food spoils in silent refrigerators.Yet, people began to understand how electricity works only a little more than two centuries ago. Nature has apparently been experimenting in this field for millions of years. Scientists are discovering more and more that the living world may hold many interesting secrets of electricity that could benefit humanity.

  All living cells send out tiny pulses of electricity. As the heart beats, it sends out pulses of record; they form an electrocardiogram, which a doctor can study to determine how well the heart is working. The brain, too, sends out brain waves of electricity, which can be recorded in an electroencephalogram. The electric currents generated by most living cells are extremely small —— often so small that sensitive instruments are needed to record them. But in some animals, certain muscle cells have become so specialized as electrical generators that they do not work as muscle cells at all. When large numbers of these cells are linked together, the effects can be astonishing.

  The electric eel is an amazing storage battery. It can send a jolt of as much as eight hundred volts of electricity through the water in which it lives. (An electric house current is only one hundred twenty volts.) As many as four-fifths of all the cells in the electric eel's body are specialized for generating electricity, and the strength of the shock it can deliver corresponds roughly to the length of its body.

  当今时代是电气时代。人们对电灯、收音机、电视和电话早已司空见惯以致很难想象没有它们生活会变成什么样。当停电时,人们在摇曳不定的烛光下暗中摸索;因没有红绿灯的指示,汽车在道路上迟疑不前;冰箱也停止工作,导致食物变质。人们只是在两个世纪前一点才开始了解电的使用原理,自然界却显然在这方面经历过了数百万年。科学家不断发现许多生物世界里可能有益于人类的关于电的有趣秘密。所有生物细胞都会发出微小的电脉冲。当心脏跳动时,把它发出的脉冲记录下来就成了心电图,这可让医生了解心脏的工作状况。大脑也发出脑电波,这可在脑电图上记录下来。许多生物细胞发出的电流都是极微小的,小到要用灵敏仪器才能记录和测量。但一些动物的某些肌肉细胞能转化成一个个发电机,以致完全失去肌肉细胞的功能。这种细胞大量地连接在一起时产生的效果将是非常令人吃惊的。电鳗就是一种令人惊异的蓄电池。它可以在水中发出相当于800伏特电压电流(家庭用户的电压只有120伏特)。在电鳗的身体里,多至五分之四的细胞都专门用来发电,而且发出的电流的强度大约和它身体的长度成正比。

  2017公共英语三级阅读文章二

  Television —— the most pervasive and persuasive of modern technologies, marked by rapid change and growth —— is moving into a new era, an era of extraordinary sophistication and versatility, which promises to reshape our lives and our world. It is an electronic revolution of sorts, made possible by the marriage of television and computer technologies.

  The word "television", derived from its Greek (tele: distant) and Latin (visio: sight) roots, can literally be interpreted as sight from a distance. Very simply put, it works in this way: through a sophisticated system of electronics, television provides the capability of converting an image(focused on a special photoconductive plate within a camera) into electronic impulses, which can be sent through a wire or cable. These impulses, when fed into a receiver (television set), can then be electronically reconstituted into that same image.

  Television is more than just an electronic system, however. It is a means of expression, as well as a vehicle for communication, and as such becomes a powerful tool for reaching other human beings.

  The field of television can be divided into two categories determined by its means of transmission. First, there is broadcast television, which reaches the masses through broad-based airwave transmission of television signals. Second, there is nonbroadcast television, which provides for the needs of individuals or specific interest groups through controlled transmission techniques.

  Traditionally, television has been a medium of the masses. We are most familiar with broadcast television because it has been with us for about thirty-seven years in a form similar to what exists today. During those years, it has been controlled, for the most part, by the broadcast networks, ABC, NBC, and CBS, who have been the major purveyors of news, information, and entertainment. These giants of broadcasting have actually shaped not only television but our perception of it as well. We have come to look upon the picture tube as a source of entertainment, placing our role in this dynamic medium as the passive viewer.