题目内容
TEXT ATelecommunications stand for devices and systems that transmit electronic or optical signals across long distances. Telecommunications enables people around the world to contact one another, to access information instantly, and to communicate from remote areas. Telecommunications usually involves a sender of information and one or more recipients linked by a technology, such as a telephone system, that transmits information from one place to another. Telecommunications enables people to send and receive personal messages across town, between countries, and to and from outer space. It also provides the key medium for delivering news, data, information, and entertainment. Telecommunications devices convert different types of information, such as sound and video, into electronic or optical signals. Electronic signals typically travel along a medium such as copper wire or are carried over the air as radio waves. Optical signals typically travel along a medium such as strands of glass fibers. When a signal reaches its destination, the device on the receiving end converts the signal back into an understandable message, such as sound over a telephone, moving images on a television, or words and pictures on a computer screen. Telecommunications messages can be sent in a variety of ways and by a wide range of devices. The messages can be sent from one sender to a single receiver (point-to-point) or from one sender to many receivers (point-to-multipoint). Personal communications, such as a telephone conversation 15etween two people or a facsimile (fax) message (see Facsimile Transmission), usually involve point-to-point transmission. Point-to-multipoint telecommunications, often called broadcasts, provide the basis for commercial radio and television programming. Telecommunications begin with messages that are converted into electronic or optical signals. Some signals, such as those that carry voice or music, are created in an analog or wave format, but may be converted into a digital or mathematical format for faster and more efficient transmission. The signals are then sent over a medium to a receiver, where they are decoded back into a form that the person receiving the message can understand. There are a variety of ways to create and decode signals, and many different ways to transmit signals. Individual people, businesses, and governments use many different types of telecommunications systems. Some systems, such as the telephone system, use a network of cables, wires, and switching stations for point-to-point communication. Other systems, such as radio and television, broadcast radio signals over the air that can be received by anyone who has a device to receive them. Some systems make use of several types of media to complete a transmission. For example, a telephone call may travel by means of copper wire, fiber-optic cable, and radio waves as the call is sent from sender to receiver. All telecommunications systems are constantly evolving as telecommunications technology improves. Many recent improvements, for example, offer high-speed broadband connections that are needed to send multimedia information over the Internet. Personal computers have pushed the limits of the telephone system as more and more complex computer messages are being sent over telephone lines, and at rapidly increasing speeds. This need for speed has encouraged the development of digital transmission technology. The growing use of personal computers for telecommunications has increased the need for innovations in fiber-optic technology. Telecommunications and information technologies are merging and converging. This means that many of the devices now associated with only one function may evolve into more versatile equipment. This convergence is already happening in various fields. Some telephones and pagers are able to store not only phone numbers but also names and personal information about callers. Wireless phones with keyboards and small screens can access the Internet and send and receive email messages. Personal computers can now access information and video entertainment and are in effect becoming a combined television set and computer terminal. Television sets can access the Internet through add-on appliances. Future modifications and technology innovations may blur the distinctions between appliances even more. Convergence of telecommunications technologies may also trigger a change in the kind of content available. Both television and personal computers are likely to incorporate new multimedia, interactive, and digital features. However, in the near term, before the actualization of a fully digital telecommunications world, devices such as modems will still be necessary to provide an essential link between the old analog world and the upcoming digital one. In this passage, "optical" can be understood as related to.
查看答案
搜索结果不匹配？点我反馈
更多问题
TEXT E Practically speaking, the artistic maturing of the cinema was the single-handed achievement of David W. Griffith (1875-1948). Before Griffith, photography in dramatic films consisted of little more than placing the actors before a stationary camera and showing them in full length as they would have appeared on stage. From the beginning of his career as a director, however, Griffith, because of his love of Victorian painting, employed composition. He conceived of the camera image as having a foreground and rear ground, as well as the middle distance preferred by most directors. By 1910 he was using close-ups to reveal significant details of the scene or of the actors. The exploitation of the camera’s possibilities produced novel dramatic effects. By splitting an event into fragments and recording each from the most suitable camera position, he could significantly vary the emphasis from camera shot to camera shot. Griffith also achieved dramatic effects by means of creative editing. By juxtaposing images and varying the speed and rhythm of their presentation, he could control the dramatic intensity of the events as the story progressed. Despite the reluctance of his producers, who feared that the public would not be able to follow a plot that was made up of such juxtaposed images, Griffith persisted, and experimented as well with other elements of cinematic syntax that have become standard ever since. These included the flashback, permitting broad psychological and emotional exploration as well as narrative that was not chronological, and the crosscut between two parallel actions to heighten suspense and excitement. In thus exploiting fully the possibilities of editing, Griffith transposed devices of the Victorian novel to film and gave film mastery of time as well as space. Besides developing the cinema’s language, Griffith immensely broadened its range and treatment of subjects. His early output was remarkably eclectic: it included not only the standard comedies, melodramas, westerns, and thrillers, but also such novelties as adaptations from Browning and Tennyson, and treatments of social issues. As his successes mounted, his ambitions grew, and with them the whole of American cinema. When he remade Enoch Arden in 1911, he insisted that a subject of such importance could not be treated in the then conventional length of one reel. Griffith’s introduction of the American-made multireel picture began an elaborate historical and philosophical spectacle. It reached the unprecedented length of four reels, or one hour’s running time. From our contemporary viewpoint, the pretensions of this film may seem a trifle ludicrous, but at the time it provoked endless debate and discussion and gave a new intellectual respectability to the cinema. As can be gathered from the passage, before 1910 the normal running time of a film was probably ______.
TEXT C During the first half of the seventeenth century, when the nations of Europe were quarreling over who owned the New World, the Dutch and the Swedes founded competing villages ten miles apart on the Delaware River. Not long afterward, the English took over both places and gave them new names, New Castle and Wilmington. For a century and a half the two villages grew rapidly, but gradually Wilmington gained all the advantages. It was a little closer to Philadelphia, so when new textile mills opened, they opened in Wilmington, not in New Castle. There was plenty of water power from rivers and creeks at Wilmington, so when young Irenee DuPont chose a place for his gunpowder mill, it was Wilmington he chose, not New Castle. Wilmington became a town and then a city—a rather important city, much the largest in Delaware. And New Castle, bypassed by the highways and waterways that made Wilmington prosperous, slept ten miles south on the Delaware River. No two villages with such similar pasts could have gone such separate ways. Today no two places could be more different. Wilmington, with its expressways and parking lots and all its other concrete ribbons and badges, is a tired old veteran of the industrial wars and wears a vacant stare; Block after city block where people used to live and shop is broken and empty. New Castle never had to make way for progress and therefore never had any reason to tear down its Seventeenth-and eighteenth-century houses. So they are still here, standing in tasteful rows under ancient elms around the original town green. New Castle is still an agreeable place to live. The pretty buildings of its quiet past make a serene setting for the lives of 4,800 people. New Castle may be America’s loveliest town, but it is .not an important town at all. Progress passed it by. Poor New Castle. Lucky Wilmington. What does the author mean by the word "progress" in this passage
按照剧情，王洛宾和卓玛同骑一匹马。王洛宾拘谨地坐在卓玛的身后，双手紧紧地抓住马鞍。卓玛忽然纵马疾驰。王洛宾被猛地一颠，身子向后仰去，惊慌中本能地拦腰抱住卓玛，这才没有落下马去。跑出很远很远，卓玛放松马缰递到他手中，任他扬鞭跃马，似乎把自己的命运也给了王洛宾。 黄昏牧归，王洛宾随着卓玛清点羊只人圈。王洛宾想着白天的情景，痴痴地望着披一身晚霞的卓玛。卓玛感觉到了异族青年那双灼人的眼睛，她慢慢地关闭栅栏，那张绯红的笑脸对着王洛宾，两只眼睛满是柔情。忽然，她举起手中的牧鞭，轻轻地打在王洛宾身上，然后转身跑去，远处草原上传来她清脆的笑声……
TEXT C During the first half of the seventeenth century, when the nations of Europe were quarreling over who owned the New World, the Dutch and the Swedes founded competing villages ten miles apart on the Delaware River. Not long afterward, the English took over both places and gave them new names, New Castle and Wilmington. For a century and a half the two villages grew rapidly, but gradually Wilmington gained all the advantages. It was a little closer to Philadelphia, so when new textile mills opened, they opened in Wilmington, not in New Castle. There was plenty of water power from rivers and creeks at Wilmington, so when young Irenee DuPont chose a place for his gunpowder mill, it was Wilmington he chose, not New Castle. Wilmington became a town and then a city—a rather important city, much the largest in Delaware. And New Castle, bypassed by the highways and waterways that made Wilmington prosperous, slept ten miles south on the Delaware River. No two villages with such similar pasts could have gone such separate ways. Today no two places could be more different. Wilmington, with its expressways and parking lots and all its other concrete ribbons and badges, is a tired old veteran of the industrial wars and wears a vacant stare; Block after city block where people used to live and shop is broken and empty. New Castle never had to make way for progress and therefore never had any reason to tear down its Seventeenth-and eighteenth-century houses. So they are still here, standing in tasteful rows under ancient elms around the original town green. New Castle is still an agreeable place to live. The pretty buildings of its quiet past make a serene setting for the lives of 4,800 people. New Castle may be America’s loveliest town, but it is .not an important town at all. Progress passed it by. Poor New Castle. Lucky Wilmington. What is Wilmington like now
微信支付 
支付宝支付