阅读理解

　　Under proper conditions, sound waves are reflected from a hillside or other such obstruction

　　(障碍物)．Sound travels at a speed of about one-fifth of a mile per second．If the hill is eleven hundred feet away, it takes two seconds for the sound to travel to the hill and back．Thus by measuring the time between a sound and its reflection the echo(回声), you can calculate(计算)the distance to an obstruction．

　　During World WarⅡ the British made a practical use of this rule to discover German planes on their way to bomb(轰炸)London long before the enemy was near the object．They used radio waves instead of sound waves, since radio waves can pass through fog and clouds．The outnumbered Royal Air Force(RAF)(皇家空军)always seemed to be lying in wait at the right time and the puzzled Germans never to be surprised．It was radio echoes more than anything else that won the Battle of Britain．

　　Since the radio waves were used to tell the direction in which to send the RAF planes and the distance to send them［their range(距离范围)of flight, in other words］, the device(装置)was called radio directing and ranging, and from the first letters the word radar(雷达)was formed．

阅读理解

People living on part of the south coast of England face a serious problem．In 1993, the owners of a large hotel and of several houses discovered, to their horror, that their gardens had disappeared overnight．The sea had eaten into the soft limestone cliffs on which they had been built．While experts were studying the problem, the ?hotel? and several houses disappeared altogether, sliding down the cliff and into the sea．Erosion(侵蚀)of the white cliffs along the south coast of England has always been a problem but it has become more serious in recent years．Dozens of homes have had to be abandoned as the sea has crept farther and farther inland．Experts have studied the areas most affected and have drawn up a map for local people, forecasting the year in which their homes will be swallowed up by the hungry sea．Angry owners have called on the Government to erect sea defenses to protect their homes．Government surveyors have pointed out that in most cases, this is impossible．New sea walls would cost hundreds of millions of pounds and would merely make the waves and currents go further along the coast, shifting the problem from one area to another．The danger is likely to continue, they say, until the waves reach an inland area of hard rock which will not be eaten as limestone is．Meanwhile, if you want to buy a cheap house with an uncertain future, apply to a house agent in one of the threatened areas on the south coast of England．You can get a house for a knockdown price but it may turn out to be a knockdown home．

阅读理解

　　What makes a person a scientist? Does he have ways or tools of learning that are different from those of others? The answer is “no”．It isn’t the tools a scientist uses but how he uses these tools which makes him a scientist．You will probably agree that knowing how to use a power is important to a carpenter(木匠)．You will probably agree, too, that knowing how to investigate(调查), how to discover information, is important to everyone．The scientist, however, goes one step further；he must be sure that he has a reasonable answer to his questions and that his answer he gets to many questions is into a large set of ideas about how the world works．

　　The scientist’s knowledge must be exact．There’s no room for half right or right just half the time．He must be as nearly right as the conditions permit．What works under one set of conditions at one time must work under the same conditions at other times．If the conditions are different, any changes the scientist observes in a demonstration(实证)must be explained by the changes in the conditions．This is one reason why investigations are important in science．Albert Einstein, who developed the Theory?of Relativity, arrived at this theory through mathematics．The accuracy(正确性)of his mathematics was later tested through investigation．Einstein’s ideas were proved to be correct．A scientist uses many tools for measurements．Then the measurements are used to make mathematical calculations(计算)that may test his investigations．

阅读理解

　　At Dallm/Fort Worth Airport, the lights are controlled by sensors that measure sunlight．They dim immediately when it’s sunny and brighten when a passing cloud blocks the sun．

　　A wall of windows at a University of Pennsylvania engineering budding has built-in blinds(百叶窗)controlled by a computer program that follows the sun’s path．

Buildings are getting smarter－and the next generation of building materials is expected to do even more．

　　Windows could catch the sun’s energy to heat water．Sensors that measure the carbon dioxide breathed out by people in a room could determine whether the air conditioning needs to be turned up．

　　Many new materials and technology have been designed in the last 15 years．They are now being used in a wave of buildings designed to save as much energy as possible．They include old ideas, like “green roofs”, where a belt of plants on a roof helps the building keep heat in winter and stay cool in summer, and new ideas, like special coating for windows that lets light in, but keeps heat out．

　　As technologies such as sensors become cheaper, their uses spread．

　　The elevators(电梯)at Seven World Trade Center, which is under construction in New York, use a system that groups people traveling to nearby floor into the same elevator, thus saving elevator stops．People who work in the building will enter it by swiping(刷)ID cards that will tell the elevators their floor; readouts will then tell them which elevator to use．The building also has windows with a coating that blocks heat while letting in light．

　　More new building materials and technology are in development．A Philadelphia building farm is now working on “smart wrap” that uses tiny solar collectors to catch the sun’s energy and transmitters(传感器)the width of a human hair to move it．They are expected to change the face of the construction industry in the next ten years or so．

阅读理解

　　Juanito Estrella has been a housekeeping manager on the US-based large passenger ship Carnival Spirit for 18 months and feels he has found the suitable position in his career(职业)．He has always wanted to travel．“I guess I am a really restless spirit．I like traveling, so when the chance came, I jumped at it, ” he says．

　　The chance came in the form of a newspaper advertisement for work on cruise ships(游船)．At the time Estrella was the housekeeping manager at a Melbourne hotel．He applied and, after two interviews, a medical check and police clearance, the job was his．

　　Estrella is responsible(负责的)for the cleanliness of the ship, making sure that 160 crew work properly．“I enjoy it because there is no other work－you wake up each day in a different place and a different culture．It’s exciting when you go to the next country and you don’t understand the language, ” he says．

　　Estrella likes being busy and getting to know people from all over the world．The 1000 crew come from 94 countries, and Estrella has learnt Spanish and a little Croatian．

　　But there is a downside．“You cannot get really drunk because you have safety responsibilities to yourself and others, ” he says．“You don’t really think about home．You start to think about home only when you get closer to your vacation and wonder what you’ll be doing．”

　　Life on the ship is anything but cruising．Estrella and his fellows work at least 10 hours a day, seven days a week．He warns the job is not for everybody．“You have to love being busy and be prepared to work every day－and to give up drinking too much alcohol．” In his spare time, if the ship sails into a prot, Estrella explores it, otherwise he works out in the crew’s gym, goes on the internet or calls home．

阅读理解

　　At first Kate thought the Romanian girl could not speak and understand English．Nadia would not reply to anything Kate said．Kate was in charge of showing Nadia around on her first day at Buckminster Grade School．Kate could not figure out why the school had put Nadia in a class where she could not understand what people were saying．

　　“Why did they do this?” Kate wondered aloud, “I mean, you can’t learn if you can’t understand the teacher．”

　　Nadia’s voice was a whisper．“I understand English．I will learn．”Nadia’s English was perfect．

　　Kate was perplexed．She couldn’t understand why Nadia did not like to speak．Then she realized that moving to a new country probably wasn’t the easiest thing to do．There were hundreds of unfamiliar and unusual things to learn－all at the same time．

　　“There’re a lot of new things to learn, huh?” said Kate．

　　Nadia nodded rapidly．In a quiet voice she replied, “Many things people say, I do not understand．I have been speaking English and Romanian all my life, but I do not know what some children are saying．For example, yesterday a boy asked if I could help him find the USB port on a thin black box he was carrying．Isn’t a port a place for ships? It made no sense to me．”

　　“Don’t worry, ”said Kate, “you’ll figure everything out in time．You see, that thin black box was a computer．A USB port is a place where you can connect other machines to a computer．”

　　Nadia and Kate were quiet after that．They took notes while the teacher gave a maths lesson．

　　To Kate’s surprise, Nadia put up her hand and offered to answer questions at the blackboard．

　　Nadia handled every question the teacher gave her．Some of the questions were really difficult, and no one understood what was going on except Nadia and the teacher．When the teacher said that Nadia answered everything correctly, the whole class clapped their hands．

　　Nadia was smiling when she sat back down next to Kate．“Some things, ”she said in a normal voice, “are the same all over the world．”

阅读理解

　　London has a new magazine, but it is not printed on paper．Everyone who has a television can receive it because it is on TV．

　　In order to read this magazine you have to have a decoder．Each page of it is numbered, so you only have to dial the number to choose which subject you want to read about．There is a wide choice－everything is included from cooking to the latest sports news．

　　If you want to read the news, the first thing you have to do is to turn to the index(索引)page which has an easy-to-remember page number, 100 for example．Then you start choosing what you want to read．The news is on pages 101 to 109 so you push out the numbers and the news appears written across your screen．Perhaps you want to go out in the afternoon, so you press 181, and a brightly colored weather map appears on the screen．But the weather is terrible, so you decide to go shopping and dial 162 for a list of the week’s best bargains．But should you drive or take the train? To answer that question you only have to press 189 for the traffic report．It is very simple to use．But probably the best thing about the service is that it is being updated all the time．Journalists type new material directly onto the screen and whole pages of the magazine can be replaced in minutes．

　　London already has three services．One, transmitted by ITV, is called ORACLE while the other two, on BBC, are called CEEFAX because they let you see facts．Although CEEFAX and ORACLE have been operating for some time, they have not been well publicized．BBC engineers do not think that their idea will ever replace books and newspapers because they can be taken with you everywhere．But many people would agree that this is a breakthrough as great as the invention of printing, which could change not just our reading habits but our whole way of life．

阅读理解

　　Now net fiction(小说), also called computer fiction is popular in more than 80 countries．

　　To write computer fictions, the writers don’t have to think about making any plot．Like reporters, they just go to a lot of places and collect materials：what most women want, their ideas about life and love, their happiness and sufferings and emotions．All these materials are fed into the computer to be processed(处理)and classified(分类)．Then the writers just pick some materials from every part and fill in some details(细节)and a story is made up．

　　The first computer fiction was edited by 13 editors and published in Canada in 1976．It was a great success and 45 million copies were sold．Seeing this new process as profit taking(赢利的)a big American publishing company bought over the majority of the 13 Canadian editors and soon a series of computer fictions were published in the United States．

　　All the computer fictions have very romantic(浪漫的)titles．The heroine(女主人公)is always about 20, while the hero is a 30 to 40 bachelor(单身的), handsome, with money and power．The hero and the heroine have a happy reunion(团聚)after all kinds of misunderstandings(误会)．Computer fictions are enjoyed by most women readers of the west．But people doubt if they have any literary value(文学价值)．

阅读理解

　　The house was quiet at 5 a. m. and Tim’s mother was asleep．Only the sound of the big freezer broke the quiet．He’d dreamt of the cave last night．The purring(轻微颤动声)of the freezer had been the sea．

　　Tim pulled on a sweater and put some apples into his schoolbag．It was too early for breakfast．He’d eat after he’d been through the cave, sitting on the rocks and staring at the sea．

　　He wished he had a proper pack．His schoolbag would have to do．What else? Sandwiches－but his mother might wake up if he started pulling out bread for sandwiches, she’d want to know why he had to leave so early．He settled for some biscuits, and left a note stuck to the table：

　　Gone to Michael’s．Back tonight．Tim．

　　The sky was high and soft and light outside．Though the sun still wasn’t up．Even the highway up the hill was quiet as he made his way down the street．The wind from the sea was fresh and sweet．

　　The sandhills still breathed heat from yesterday’s sun, though the top of the sand was cool．He ran down to the beach impatiently, but there was no one, just dry sand dancing in the early wind and seabirds marching up and down watching the waves．

　　The light changed suddenly．The first rays of sunlight stretched(延伸)across the sea．The sun was pushing its way over the edge of the world．

　　Over the first rocks, along to the point．Tim glanced back．The beach was still empty．The sun sailed higher in the sky．

　　He could see the cave now, even darker in the morning light．The sand turned silver then dark gold as the water flowed away from it．He had to force himself to go closer．Why was it so much more mysterious(神秘的)now? But it would be silly to go back now after so much trouble．He needn’t go in all the way…

阅读理解

　　Jane Austen, a famous English writer, was born at Steventon, Hampshire, on December 16, 1775, and died on July 18, 1817．She began writing early in life, although the prejudices(偏见)of her times forced her to have her books published anonymously(匿名)．

　　But Jane Austen is perhaps the best known and best loved of Bath’s many famous local people and visitors．She paid two long visits here during the last five years of the eighteenth century and from 1801 to 1806, Bath was her home．Her deep knowledge of the city is fully seen in two of her novels, Northanger Abbey and Persuasion, which are largely set in Bath．The city is still very much as Jane Austen knew it, keeping in its streets and public buildings the well-ordered world that she described so well in her novels．Now the pleasure of learning Jane Austen’s Bath can be enhanced(增强)by visiting the Jane Austen Centre in Gay Street．Here, in a Georgian town house in the heart of the city, you can find out more about Bath in Jane Austen’s time and the importance of Bath in her life and work．

　　The Center has been set up with the help and guidance of members of the Jane Austen Society．After your visit to the Center, you can look round the attractive shop, which offers a huge collection of Jane Austen related books, cards and many specially designed gifts．Jane Austen quizzes are offered to keep the children busy．

　　You can also have walking tours of Jane Austen’s Bath, which is a great way to find out more about Jane Austen and discover the wonderful Georgian city of Bath．The tour lasts about one and a half hours．The experienced guides will take you to the places where Jane lived, walked and shopped．