The American Revolution was not a revolution in the sense of a radical or toal change .It was not a sudden and violent overturning of the political and social framework, such as later occurred in France and Russia, when both were already independent nations. Significant changes were ushered(引导，展示) in, but they were not breathtaking(惊人的，惊险的). What happened was accelerated evolution rather than outright(直率的，彻底的) revolution. During the conflict itself people went on working and praying, marrying and playing. Most of them were not seriously disturbed by the actual fighting, and many of the more isolated communities scarcely knew that a war was on.
America's War of Independence heralded(预报，宣布) the birth of three modern nations. One was Canada, which received its first large influx(注入，流入) of English-speaking population from the thousands of loyalists(忠诚的人，反对独立的人) who fled there from the United States. Another was Australia, which became a penal(刑事的) colony now that America was no longer available for prisoners and debtors. The third newcomer-the United States-based itself squarely on republican principles.
Yet even the political overturn was not so revolutionary as one might suppose. In some states, notably Connecticut and Rhode Island, the war largely ratified a colonial self-rule already existing. British officials, everywhere ousted, were replaced by a home-grown governing class, which promptly sought a local substitute for king and Parliament.(现在就算是政治革命也不如以前想像的那样具有革命性。在一些州，特别明显的像康涅狄格和瑞候德岛，战争在很大程度上批准一些殖民居住地自治的做法已经存在。英国政府到处掠夺，它被本国的政治阶层所取代，而这个政治阶层很快地在当地为国王和国会找到本国的替代品)
Andrew Carnegie, known as the King of Steel, built the steel industry in the United States, and , in the process, became one of the wealthiest men in America. His success resulted in part from his ability to sell the product and in part from his policy of expanding during periods of economic decline, when most of his competitors were reducing their investments.
Carnegie believed that individuals should progress through hard work, but he also felt strongly that the wealthy(有钱人，富人) should use their fortunes for the benefit of society. He opposed charity(施舍), preferring instead to provide educational opportunities that would allow others to help themselves. "He who dies rich, dies disgraced," he often said.
Among his more noteworthy contributions to society are those that bear his name, including the Carnegie Institute of Pittsburgh, which has a library, a museum of fine arts, and a museum of national history. He also founded a school of technology that is now part of Carnegie-Mellon University. Other philanthrophic gifts are the Carnegie Endowment for International Peace to promote understanding between nations, the Carnegie Institute of Washington to fund scientific research, and Carnegie Hall to provide a center for the arts.
Few Americans have been left untouched by Andrew Carnegie's generosity(慷慨，大方). His contributions of more than five million dollars established 2,500 libraries in small communities throughout the country and formed the nucleus of the public library system that we all enjoy today.
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(摸索) about in flickering candlelight, cars hesitate in the streets because there are no traffic lights to guide them, and food spoils(损坏，宠坏，弄糟) 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 million 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 cell send out tiny pulses(脉冲) 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.(但是一些动物它们特定的肌肉细胞已经变得和发电机一样，但是发电机的工作原理和它们完全不一样) When large numbers of these cell are linked together, the effects can be astonishing.
The electric eel is an amazing storage battery. It can seed a jolt of as much as eight hundred volts of electricity through the water in which it live. ( 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 length of its body.
If by "suburb" is meant an urban margin that grows more rapidly than its already developed interior, the process of suburbanization began during the emergence of the industrial city in the second quarter of the nineteenth century. Before that period the city was a small highly compact cluster in which people moved about on foot and goods were conveyed by horse and cart. But the early factories built in the 1840's were located along waterways and near railheads at the edges of cities, and housing was needed for the thousands of people drawn by(由……拉动) the prospect of employment. In time, the factories were surrounded by proliferating(增生扩散) mill towns of apartments and row houses that abutted(v.邻接，毗邻) the older, main cities. As a defense against this encroachment(侵蚀) and to enlarge their tax bases, the cities appropriated their industrial neighbors. In 1854, for example, the city of Philadelphia annexed(并吞，附加) most of Philadelphia County. Similar municipal maneuvers took place in Chicago and in New York. Indeed, most great cities of the United States achieved such status only by incorporating the communities along their borders.
With the acceleration of industrial growth came acute urban crowding and accompanying social stress-conditions that began to approach disastrous proportions when, in 1888, the first commercially successful electric traction line was developed. Within a few years the horse-drawn trolleys were retired and electric streetcar networks crisscrossed and connected every major urban area, fostering a wave of suburbanization that transformed the compact industrial city into a dispersed metropolis. This first phase of mass-scale suburbanization was reinforced by the simultaneous emergence of the urban Middle Class, whose desires for homeownership in neighborhoods far from the aging inner city were satisfied by the developers of single-family housing tracts.
Television-----the most pervasive(弥漫性的，渗透性的) and persuasive(有说服力的，使人信服的) of modern technologies, marked by rapid change and growth-is moving into a new era, an era of extraordinary(非凡的) sophistication and versatility(多功能性), which promises to reshape our lives and our world. It is an electronic revolution of sorts(各种各样的), 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(刺激，推动力), 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(承办商)of news, information, and entertainment. These giants of broadcasting have actually shaped not only television but our perception(感觉) 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.(我们作为被动的观众把我们的角色溶入这种动态的媒体，我们已经开始把显像管看做一种娱乐的资源。)
There are many theories about the beginning of drama in ancient Greece. The one most widely accepted today is based on the assumption that drama evolved from ritual(典礼，宗教仪式). The argument for this view goes as follows. In the beginning, human beings viewed the natural forces of the world-even the seasonal changes-as unpredictable, and they sought through various means to control these unknown and feared powers. Those measures which appeared to bring the desired results were then retained and repeated until they hardened into fixed rituals. Eventually stories arose which explained or veiled(以面纱遮盖，隐避) the mysteries of the rites(仪式，典礼). As time passed some rituals were abandoned, but the stories, later called myths, persisted and provided material for art and drama.
Those who believe that drama evolved out of ritual also argue that those rites contained the seed of theater because music, dance, masks, and costumes(服装) were almost always used, Furthermore, a suitable site had to be provided for performances and when the entire community did not participate, a clear division was usually made between the "acting area" and the "auditorium." In addition, there were performers, and, since considerable importance was attached to avoiding mistakes in the enactment(设定制定) of rites, religious leaders usually assumed that task. Wearing masks and costumes, they often impersonated other people, animals, or supernatural beings, and mimed(模仿) the desired effect-success in hunt or battle, the coming rain, the revival of the Sun-as an actor might. Eventually such dramatic representations were separated from religious activities.
Another theory traces the theater's origin from the human interest in storytelling. According to this views tales (about the hunt, war, or other feats) are gradually elaborated, at first through the use of impersonation, action, and dialogue by a narrator and then through the assumption of each of the roles by a different person. A closely related theory traces theater to those dances that are primarily rhythmical and gymnastic or that are imitations of animal movements and sounds.
Prices determine how resources are to be used.(价格决定多少资源被使用) They are also the means by which products and services that are in limited supply are rationed among buyers.(它们也是有限的产品和服务在购买者之间按比例分配的依据) The price system of the United States is a complex network composed of the prices of all the products bought and sold in the economy as well as those of a myriad of(无数的) services, including labor, professional, transportation, and public-utility services. The interrelationships of all these prices make up the “system” of prices. The price of any particular product or service is linked to a broad, complicated system of prices in which everything seems to depend more or less upon everything else.
If one were to ask a group of randomly selected individuals to define “price”, many would reply that price is an amount of money paid by the buyer to the seller of a product or service or, in other words that price is the money values of a product or service as agreed upon in a market transaction. This definition is, of course, valid as far as it goes. For a complete understanding of a price in any particular transaction, much more than the amount of money involved must be known. (为了在任一个特定的交易中透彻地了解价格的含义，需要了解除钱的数量之外所涉及的更多内容) Both the buyer and the seller should be familiar with not only the money amount, but with the amount and quality of the product or service to be exchanged, the time and place at which the exchange will take place and payment will be made, the form of money to be used, the credit terms and discounts(折扣) that apply to the transaction, guarantees on the product or service, delivery terms, return privileges(特权，特别待遇), and other factors. In other words, both buyer and seller should be fully aware of all the factors that comprise the total “package” being exchanged for the asked-for amount of money in order that they may evaluate a given price. (换句话说，为了能够评估一个给定的价格，买者和卖者都应该完全清楚组成这个总的“包裹”的所有因素，这个总的“包裹”是用来和标定的钱数来交换的)
A painter hangs his or her finished pictures on a wall, and everyone can see it. A composer writes a work, but no one can hear it until it is performed. Professional singers and players have great responsibilities, for the composer is utterly dependent on them. A student of music needs as long and as arduous(艰辛的) a training to become a performer as a medical student needs to become a doctor. Most training is concerned with technique, for musicians have to have the muscular proficiency of an athlete or a ballet dancer. Singers practice breathing every day, as their vocal(声音的) chords(和音) would be inadequate without controlled muscular support. String players practice moving the fingers of the left hand up and down, while drawing the bow to and fro with the right arm—two entirely different movements.
Singers and instruments have to be able to(能够，可以) get every note perfectly in tune. Pianists are spared this particular anxiety, for the notes are already there, waiting for them, and it is the piano tuner's responsibility to tune the instrument for them. But they have their own difficulties; the hammers that hit the string have to be coaxed not to sound like percussion, and each overlapping tone has to sound clear.
This problem of getting clear texture is one that confronts student conductors: they have to learn to know every note of the music and how it should sound, and they have to aim at controlling these sound with fanatical(狂热的) but selfless authority. (with A but B,是A而不是B)
Technique is of no use unless it is combined with musical knowledge and understanding. Great artists are those who are so thoroughly at home in the language of music that they can enjoy performing works written in any century.
Standard usage includes those words and expressions understood, used, and accepted by a majority of the speakers of a language in any situation regardless of the level of formality. As such, these words and expressions are well defined and listed in standard dictionaries. Colloquialisms, on the other hand, are familiar words and idioms that are understood by almost all speakers of a language and used in informal speech or writing, but not considered appropriate for more formal situations. Almost all idiomatic expressions are colloquial language. Slang, however, refers to words and expressions understood by a large number of speakers but not accepted as good, formal usage by the majority. Colloquial expressions and even slang may be found in standard dictionaries but will be so identified. Both colloquial usage and slang are more common in speech than in writing.
Colloquial speech often passes into standard speech. Some slang also passes into standard speech, but other slang expressions enjoy momentary popularity followed by obscurity. In some cases, the majority never accepts certain slang phrases but nevertheless retains them in their collective memories. Every generation seems to require its own set of words to describe familiar objects and events. It has been pointed out by a number of linguists that three cultural conditions are necessary for the creation of a large body of slang expressions. First, the introduction and acceptance of new objects and situations in the society; second, a diverse population with a large number of subgroups; third, association among the subgroups and the majority population.
Finally, it is worth noting that the terms "standard" "colloquial" and "slang" exist only as abstract labels for scholars who study language. Only a tiny number of the speakers of any language will be aware that they are using colloquial or slang expressions. Most speakers of English will, during appropriate situations, select and use all three types of expressions.