单选题How the First Stars in the Universe Came into Existence How the first stars formed from this dust and gas has been a burning question for years, but a state-of-the-art computer simulation now offers the most detailed picture yet of how these first stars in the universe came into existence, researchers say. The composition of the early universe was quite different from that of today, and the physics that governed the early universe were also somewhat simpler. Dr. Naoki Yoshida and colleagues in Japan and the U.S. incorporated these conditions of the early universe, sometimes referred to as the "cosmic dark ages," to simulate the formation of an astronomical object that would eventually shine its light into this darkness. The result is a detailed description of the formation of a protostar--the early stage of a massive primordial star of our universe, and the researchers' computer simulation, which has been called a "cosmic Rosetta Stone" sets the bar for further investigation into the star formation process. The question of how the first stars evolved is so important because their formations and eventual explosions provided the seeds for subsequent stars to come into being. According to their simulation, gravity acted on minute density variations in matter, gases, and the mysterious "dark matter" of the universe after the Big Bang in order to form this early stage of a star-a protostar with a mass of just one percent of our sun. The simulation reveals how pre-stellar gases would have actually evolved under the simpler physics of the early universe to form this protostar. Dr. Yoshida's simulation also shows that the protostar would likely evolve into a massive star capable of synthesizing heavy elements, not just in later generations of star, but soon after the Big Bang. "This general picture of star formation, and the ability to compare how stellar objects form in different time periods and regions of the universe, will eventually allow investigation into the origins of life and planets," said Lars Hernquist, a Professor of Astronomy at Harvard University and a coauthor of this latest report. "The abundance of elements in the universe has increased as stars have accumulated," he says, "and the formation and destruction of stars continues to spread these elements further across the universe. So when you think about it all of the elements in our bodies originally formed from nuclear reactions in the centers of stars, long ago." Their simulation of the birth of a protostar in the early universe signifies a key step toward the ambitious goal of piecing together the formation of an entire primordial star and of predicting the mass and properties of these first stars of the universe. More powerful computers, more physical data, and an even larger range will be needed for further calculations and simulations, but these researchers hope to eventually extend this simulation to the point of nuclear reaction initiation when a stellar object becomes a true star. "Dr. Yoshida has taken the study of primordial star formation to a new level with this simulation, but it still gets us only to the halfway point towards our final goal. It is like laying the foundation of a skyscraper," said Volker Bromm, Assistant Professor of Astronomy at the University of Texas, Austin and the author of a companion article. "We must continue our studies in this area to understand how the initially tiny protostar grows, layer by layer, to eventually form a massive star. But here, the physics become much more complicated and even more computational resources are needed./

单选题Dark Forces Dominate Universe The earth, moon, sun and all visible stars in the sky make up less than one percent of the universe. Almost all the rest is dark matter and dark energy, unknown forces that 1 astronomers. Observations in recent years have changed the basic 2 of how the universe evolved and have indicated how little is known about the major forces and substances that 3 our world. Astronomers now know that luminous (发光的) matter—stars, planets and hot gas—accounts 4 only about 0.4 percent of the universe. Non-luminous components, such as black holes and intergalactic (星系间的) gas, 5 up 3.6 percent. The rest is either dark matter, about 23 percent, or dark energy, about 73 percent. Dark matter, sometimes 6 "cold dark matter", has been known for some time. Only recently have researchers come to understand the key role it 7 in the formation of stars, planets and even people. "We 8 our very existence to dark matter," said physicist Paul Steinhardt and a co-author of a review on dark matter which 9 not long ago in the journal Science. "Dark matter dominated the structure 10 in the early universe," Steinhardt said. "For the first few billion years dark matter contained most of the mass of the universe. You can think of ordinary matter 11 a froth (泡沫) of an ocean of dark matter. The dark matter clumps (结成块) and the ordinary matter falls into it. That 12 to the formation of the stars and galaxies (星系)." Without dark matter, "there would be virtually no structures in the universe." The nature of dark matter is 13 . It cannot be seen or detected directly. Astronomers know it is there because of its 14 on celestial (天体的) objects that can be seen and measured. But the most dominating force of all in the universe is called dark energy, a recently 15 power that astronomers say is causing the galaxies in the universe to separate at a faster and faster speed.

单选题Youth hostels provide inexpensive {{U}}lodging{{/U}} for young people throughout the United States and in other countries.

单选题 Mother Nature Shows Her Strength Tornadoes (龙卷风) and heavy thunderstorms moved across the Great Lakes and into Trumbull County on Saturday evening. The storms were dramatic and dangerous. George Snyder was driving the fire truck down Route 88 when he first noticed that a funnel (漏斗状的) cloud was behind him. "I stopped the truck and watched the funnel cloud. It was about 100 feet off the ground and I saw it go up and down for a while. It was moving toward Bradley Road and then suddenly it disappeared." Snyder said. Snyder only saw one of the funnel clouds that passed through northeastern Ohio on Saturday. In Trumbull County, a tornado turned trees onto their sides. Some trees feel onto houses and Cars. Other trees fell into telephone and electrical wires as they went down. Amanda Symcheck was having a party when the storm began. "I knew something was wrong," she said. "I saw the sky go green and pink (粉红色的). Then it sounded like a train rushing toward the house. I started crying and told everyone to go to the basement for protection." The tornado caused a lot of damage to cars and houses in the area. It will take a long time and much money to repair everything. There was also serious water damage from the thunderstorms. The heavy rains and high wind caused the power to go out in many homes. The storms caused serious flooding in areas near the river. More than four inches of rain fell in parts of Trumbull County. The river was so hight that the water ran into streets and houses. Many streets had to be closed to cars and trucks because of the high water. This made it difficult for fire trucks, police cars, and other rescue vehicles to help people who were in trouble. Many people who live near the river had to leave their homes for their own safety. Some people reported five feet of water in their homes. Local and state officials opened emergency shelters for the people who were evacuated (撤走). The Red Cross served meals to them. "This was a really intense storm." said Snyder. People were afraid. MotherNature call be fierce. We were lucky this time. No one was killed."

单选题Money and Love Paul had long promised to marry Clara. But at thirty-three he met and married Alice. Clara was driven mad. Paul was taken to court. The judge ordered him to pay Clara $600 because of the broken promise. Paul had to borrow the money from a moneylender. He agreed to pay back $5 a month—for twenty years. His wages at the time were $16 a month. Paul and Alice were poor but not unhappy. They had little enough food, certainly, even before the children began to arrive. Each month Paul paid $5 to the moneylender. He worked hard, never taking a holiday. In time, there were seven mouths to feed. Illness was always with them. It grew serious when the oldest child was eight. The years of hunger weakened the family, because each month Paul paid $5. The details of the sickness were ugly, but the result was this: After twelve years of family life, Paul was alone in the world. He lived alone, except for memories. Work was not now a god for him: it was a pain-killer. Each month he paid, and in time the twenty years ended. From that moment his wages were his own. One day, it was a holiday—he went to the seaside. He sat down on a seat by the sea. A middle-aged woman came and sat down near him. They recognized each other at once. The woman said, "The $600 has been in the bank since the day it was paid to me. It is now $6,000, and I have kept it for you. Will you let me share it with you?" "No," said Paul, gently. "Each thousand is a lost life in a desert between us. It can never bring any happiness."

单选题{{B}}第二篇{{/B}} {{B}} Lateral Thinking{{/B}} Lateral thinking (迂回思维), first described by Edward de Bono in 1967, is just a few years older than Edward’s son. You might imagine that Caspar was raised to be an adventurous thinker, but de Bono name was so famous, Casper’s parents worried that any time he would say something bright at school, his teachers might snap, “Where do you get that idea from?” “We had to be careful and not overdo it,” Edward admits. Now Casper is at Oxford —— which once looked unlikely because he is also slightly dyslexic (通读困难). In fact, when he was applying to Oxford, none of his school teachers thought he had a chance. “So then we did several thinking sessions,” his father says, “using my techniques and, when he went up for the exam, he did extremely well.” Soon after, Edward de Bono decided to write his latest book, “Teach Your Children How to Think”, in which he transforms the thinking skills he developed for brain-storming businessmen into informal exercises for parents and children to share. Thinking is traditionally regarded as something executed in a logical sequence, and everybody knows that children aren’t very logical. So isn’t it an uphill battle, trying to teach them to think? “You know,” Edward de Bono says, “if you examine people’s thinking, it is quite unusual to find faults of logic. But the faults of perception are huge! Often we think ineffectively because we take too limited a view.” “Teach Your Child How to Think” offers lessons in perception improvement, of clearly seeing the implications of something you are saying and of exploring the alternatives.

单选题I asked her if she would allow me to interview her, and she readily agreed.

单选题{{B}}第二篇{{/B}} {{B}}Underground Coal Fires A Looming Catastrophe{{/B}} Coal burning deep underground in China, India and Indonesia is threatening the environment and human life, scientists have warned. These large-scale underground blazes cause the ground temperature to heat up and kill surroundings vegetation, produce greenhouse gases and can even ignite forest fires, a panel of scientists told the annual meeting of the American Association for the Advancement of Science in Denver. The resulting release of poisonous elements like arsenic and mercury can also pollute local water sources and soils, they warned. "Coal fires are a global catastrophe," said Associate Professor Glenn Stracher of East Georgia College in Swainsboro, USA. But surprisingly few people know about them. Coal can heat up on its own, and eventually catch fire and burn, if there is a continuous oxygen supply. The heat produced is not caused to disappear and under the right combinations of sunlight and oxygen, can trigger spontaneous catching fire and burning. This can occur underground, in coal stockpiles, abandoned mines or even as coal is transported. Such fires in China consume up to 200 million tones of coal per year, delegates were told. In comparison, the US economy consumes about one billion tons of coal annually, said Stracher, whose analysis of the likely impact of coal fires has been accepted for publication in the International Journal of coal ecology, once underway, coal fires can burn for decades, even centuries. In the process, they release large volumes of greenhouse gases; poisonous gases fumes and black particles in to the atmosphere. The members of the panel discussed the impact these fires may be having on global and regional climate change, and agreed that the underground nature of the fires makes them difficult to protect. One of the members of the panel, Assistant Professor Pan1 Van Dijk of the International Institute for Goo-Information Science' and Earth Observation in the Netherlands, has been working with the Chinese government to detect and monitor fires in the northern regions of the country. Ultimately, the remote sensing and other techniques should allow scientists to estimate how much carbon dioxide theses fires are emitting. One suggested method of containing the fires was presented by Cary Colaozzi, of the engineering firm Goodson,' which bas developed a heat-resistant grout (a thin mortar used to fill cracks and crevices,) which is designed to be pumped into the coal fire to cut off the oxygen supply.

单选题The word "navigate" in Paragraph 3 means

单选题He is optimistic that he will win the election.A. positiveB. dismayedC. frustratedD. incredible

单选题 The National Trust The National Trust in Britain plays an increasingly important part in the preservation for public enjoyment of the best that is left unspoiled of the British countryside. Although the Trust has received practical and moral support from the Government, it is not a rich Government department. It is a voluntary association of people who care for the unspoiled countryside and historic buildings of Britain. It is charity which depends for its existence on voluntary support from members of the public. Its primary duty is to protect places of great natural beauty and places of historical interest. The attention of the public was first drawn to the dangers threatening the great old houses and castles of Britain by the death of Lord Lothian, who left his great seventeenth- century house to the Trust together with the 4,500-acre park and estate surrounding it. This gift attracted wide publicity and started the Trust's "Country House Scheme". Under this scheme, with the help of the Government and the general public, the Trust has been able to save and make accessible to the public about one hundred and fifty of these old houses. Last year about one and three quarters of a million people paid to visit these historic houses, usually at a very small charge. In addition to country houses and open spaces, the Trust now owns some examples of ancient wind and water mills, nature reserves, five hundred and forty farms and nearly two thousand five hundred cottages or small village houses, as well as some complete villages. In these villages no one is allowed to build, develop or disturb the old village environment in any way and all the houses are maintained in their original sixteenth-century style. Over four hundred thousand acres of coastline, woodland, and hill country are protected by the Trust and no development or disturbances of any kind are permitted. The public has free access to these areas and is only asked to respect the peace, beauty and wildlife. So it is that over the past eighty years the Trust has become a big and important organization and an essential and respected part of national life, preserving all that is of great natural beauty and of historical significance not only for future generations of Britons but also for the millions of tourists who each year invade Britain in search of a great historic and cultural heritage.

单选题The bricklayer is working on the house today.

单选题I expect that she will be able to cater for your particular needs. A. supply B. reach C. provide. D. meet

单选题The Case of the Disappearing Fingerprints One useful anti-cancer drug can effectively erase the whorls and other characteristic marks that give people their distinctive fingerprints. Losing them could become troublesome. A case (51) online in a letter by Annals of Oncology (肿瘤学) indicates how big a (52) of losing fingerprints is. Eng-Huat Tan, a Singapore-based medical doctor describes a 62-year-old man who has used capecitabine to (53) his nasopharyngeal cancer (鼻咽喉). After three years on the (54) , the patient decided to visit U. S. relatives last December. But he was stopped by U. S. customs officials (55) 4 hours after entering the country when those officials couldn't get fingerprints from the man. There were no (56) swirly marks appearing from his index finger. "U. S. customs has been fingerprinting incoming foreign visitors for years." Tan says. "unfortunately, for the Singaporean traveler, one potential (57) effect of his drug treatment is a smoothing of the tissue on the finger pads. (58) , no fingerprints." "It is uncertain when fingerprint (59) will begin to take place in patients who are taking capecitabine," Tan points out. So he (60) any physicians who prescribe the drug to provide their patients with a doctor's (61) pointing out that their medicine may cause fingerprints to disappear. Eventually, the Singapore traveler made it into the United States. I guess the name on his passport didn't raise any red flags. But he's also now got the explanatory doctor's note-and won't leave home (62) it. By the way, maybe the Food and Drug Administration (美国食品药物管理局), (63) approved use of the drug 11 years ago, should consider updating its list of side effects (64) with this medicine. The current list does note that patients may experience vomiting (呕吐), stomach pain and some other side effects. But no where (65) it mention the potential for loss of fingerprints.

单选题This was disaster on a cosmic scale.

单选题The policemen acted quickly because lives were at stake. A．in despair B．in danger C．in misery D．in pain

单选题Her faith upheld her in times of sadness. A．supported B．excited C．inspired D．directed

单选题She was a puzzle. A. girl B. woman C. mystery D. problem

单选题Across the English Channel To swim across the English Channel takes at least nine hours. It's a hard work and it makes you short of breath. To fly over the Channel takes only twenty minutes (as only as you're not held up at the airport), but it's an expensive way to travel. You can travel by hovercraft if you don't mind the noise, and that takes forty minutes. Otherwise you can go by boat, if you dreams of being able to drive to France in his own car. "Not possible", you say. Well wait a minute. People are once again considering the idea of a Channel tunnel or bridge. This time, the Greater London Council is looking into the possibility of building a Channel link straight to London. A bridge would cost far more than a tunnel, but you would be able to go by rail or by car on a bridge, whereas a tunnel would provide a rail link only. Why is this idea being discussed again? Is Britain becoming more conscious of the need for links with Europe as a result of joining the EEC (欧共体)? Well, perhaps. The main reason, though, is that a tunnel or bridge would reach the twenty square kilometers of London's disused dockland(船坞地). A link from London to the continent would stimulate trade and re-vitalize(使…重新具有活力)the port, and would make London a main trading center in Europe. With a link over the Channel, you could buy your fish and chips in England and be able to eat them in France while they were still warm!

单选题Although it is made in America, BigBelly is reminiscent(使人想起) of a futuristic Japanese robot. Flashing lights indicate when it is full and needs to be emptied. Many are wireless. enabled, which effectively turns them into Twitterers—they transmit brief text messages to a centralized Web site to let owners know when compactors are full. Like many smart green products, they're not cheap—and they're much more expensive than the dumb product they're hoping to dislodge. It costs about $ 80 a month to lease(长期租用) a BigBelly, or from $ 3,000 to $ 3,900 to purchase one, though those buying in bulk get a discount. How can BigBelly let his owner know that the compactor is full?A. By sending text messages to a centralized website.B. By turning on the flash-lights connected to the compactor.C. By sending a robot to remind the owner.D. By sending messages through Twitterers.