单选题Travel to Moon The National Aeronautics and Space Administration (NASA) has announced plans to return people to the moon by 2018. "And this time," according to a NASA press release, "we're going to stay." NASA wants to make a new spaceship for the missions using parts from the Apollo program, which first took people to the moon in 1969, and the space shuttle. NASA says the new Crew Exploration Vehicle (CEV) will be "affordable, reliable, and safe." The CEV will be able to hold four astronauts. The plan is to have the CEV dock(对接)in space with the lunar lander—the vehicle astronauts will use to land on the moon—which will be launched separately into space. The CEV will then travel to the moon and all four astronauts will walk on the moon. The first moon missions are expected to last up to seven days. Exploration and construction of a moon base will be the astronauts' top priorities (最优先考虑的事) . NASA hopes to have a minimum of two moon missions a year starting in 2018. This will allow for quick moon base construction, constant scientific study, and training for future missions to Mars.

单选题I didn't help him. I would have,Uhowever/U,I didn't have the money.

单选题 Escaping from the Earth The Earth has a force that pulls things toward itself. We call this force gravity(地心引力). This is something we live with all the time, and we take it for granted and hardly ever think about it. But it is a most important factor in rocket operation and must be overcome if we are to get anywhere in space, or off the ground at all. Take the throwing of a hall as an example. The harder the ball is thrown, the faster and higher it will go. What is the secret? Its speed. If we could throw the ball hard enough it would go up and up forever and never come down. The speed at which it would have to be thrown to do this is known as escape speed. Of course, we cannot throw a ball hard enough because the speed required to escape completely from the Earth's gravity is seven miles per second, or over twenty-five thousand miles per hour. Once escape speed has been reached by a spacecraft(宇宙飞船), no further power is needed. A rocket aimed at the Moon, for instance, will "coast"(滑行) the rest of the way be cause the Earth's gravity cannot then pull it back, and there is no air resistance(阻力) in space to slow it down. This "coasting" is known as "free fall". That does not mean the rocket is falling down towards the Earth but that it is traveling freely in space without the aid of power, like a bicycle coasting downhill. Free fall is an important feature of space travel: it would be impossible to carry enough fuel to provide powered flight all the time.

单选题We are so tired after one work on this program.

单选题He seized the opportunity to present his proposal to the teacher. A. realized B. took C. followed D. kept

单选题Her peers were her worst critics. A. students B. equals C. teachers D. subordinates

单选题Mobile Phones: Are They about to Transform Our Lives? We love them so much that some of us sleep with them under the pillow, yet we are increasingly concerned that we cannot escape their electronic reach. We use them to convey our most intimate secrets, yet we worry that they are a threat to our privacy. We rely on them more than the Internet to cope with modern life, yet many of us don't believe advertisements saying we need more advanced services. Sweeping aside the doubts that many people feel about the benefits of new third generation phones and fears over the health effects of phone masts (天线竿), a recent report claims that the long-term effects of new mobile technologies will be entirely positive so long as the public can be convinced to make use of them. Research about users of mobile phones reveals that the mobile has already moved beyond being a mere practical communications tool to become the backbone (支柱) of modern social life, from love affairs to friendship to work. One female teacher, 32, told the researchers: "I love my phone. It's my friend. " The close relationship between user and phone is most pronounced among teenagers, the report says, who regard their mobiles as an expression of their identity. This is partly because mobiles are seen as being beyond the control of parents. But the researchers suggest that another reason may be that mobiles, especially text messaging, are seen as a way of overcoming shyness. "Texting is often used for apologies, to excuse lateness or to communicate other things that make us uncomfortable," the report says. The impact of phones, however, has been local rather than global, supporting existing friendships and networks, rather than opening users to a new broader community. Even the language of texting in one area can be incomprehensible to anybody from another area. Among the most important benefits of using mobile phones, the report claims, will be a vastly improved mobile infrastructure (基础设), providing gains throughout the economy, and the provision of a more sophisticated location-based services for users. The report calls on government to put more effort into the delivery of services by mobile phone, with suggestions including public transport and traffic information and doctors' text messages to remind patients of appointments. "I love that idea," one user said in an interview. "It would mean I wouldn't have to write a hundred messages to myself. " There are many other possibilities. At a recent trade fair in Sweden, a mobile navigation product was launched. When the user enters a destination, a route is automatically downloaded to their mobile and presented by voice, pictures and maps as they drive. In future, these devices will also be able to plan around congestion (交通堵塞) and road works in real time. Third generation phones will also allow for remote monitoring of patients by doctors. In Britain scientists are developing an asthma (哮喘) management solution, using mobiles to detect early signs of an attack.

单选题{{B}}第三篇{{/B}} Hurricane (飓风) Katrina A hurricane is a fiercely powerful, rotating(旋转的)form of tropical storm that can be 124 to 1,240 miles in diameter. The term hurricane is derived from Hurican, the name of a native American storm god. Hurricanes are typical of a calm central region of low pressure between "12 to 60 miles in diameter, known as the eye. They occur in tropical regions. Over its lifetime, one of these can release as much energy as 10,000 nuclear bombs. The seed for hurricane formation is a cluster(聚集) of thunderstorm over warm tropical waters. Hurricanes can only form and be fed when the sea-surface temperature exceeds 27℃ and the surrounding atmosphere is calm. These requirements are met between June and November in the northern part of the world. Under these conditions, large quantities of water evaporate (蒸发) and condense (冷凝) into clouds and rain-releasing heat in the process. It is this heat energy, combined with the rotation of the Earth, that drives a hurricane. When the warm column of air from the sea surface first begins to rise, it causes an area of low pressure. This in turn creates wind as air is drawn into the area. This spinning wind drags up more moist air from the sea surface in a process that strengthens the storm. Cold air falls back to the ocean surface through the eye and on the outside of the storm. Initially, when wind speeds reach 23 miles per hour, these mild, wet and grey weather systems are known as depressions, or low air pressure. Hurricane Katrina formed in this way over the southeastern Bahamas on 23 August 2005, Katrina has had a devastating impact on the Gulf Coast of the US, leaving a disaster zone of 90,000 square miles in its wake(尾迹)-almost the size of the UK. Thousands have been killed or injured and more than half a million people have become homeless in a humanitarian(人道主义的) crisis of a scale not seen in the US since the Great Depression. The cost of the damage may top $100 billion.

单选题She persevered in her ideas despite obvious objections raised by friends.

单选题Her son, to whom she was so devoted , went abroad ten years ago.

单选题TapeStore: A．New Tape Storage System TapeStore is a new kind of tape storage system which can store up to 6,000 computer tapes. No other tape storage system can hold as many computer tapes as TapeStore. The tapes look exactly like video cassettes. Many hundreds of data files can be stored on each tape, up to a maximum of 500 million bytes (字节) of data. If you stored the same amount of information on paper, you would need nearly 4. 5 billion printed pages. The machine is a tall black box with a mechanical arm. The machine is 2.5 metres high and 3.0 metres wide. This is how it works. Each tape has a code printed on it. You feed the code number into TapeStore, which then looks for the code. As soon as TapeStore locates the code, the arm reaches in and pulls out the tape. The system is very fast. It takes the mechanical arm about 10 seconds to find the tape it is looking for. The machine then searches the tape to extract (提取) the required file, and this takes less than a minute. A human technician would have to locate and remove the tape by hand, and could take at least an hour to find the right file on the tape. Some of the world's biggest companies, including banks, insurance companies, airlines, telephone companies, utilities and computer centres, have bought the system. They like it particularly because the system guarantees the security of their data. TapeStore was originally developed in Canada and is now being marketed worldwide. In Europe alone, 750 have already been installed at a cost of 480,000 dollars each.

单选题Study Helps Predict Big Mediterranean Quake Scientists have found evidence that an overlooked fault in the eastern Mediterranean is likely to produce an earthquake and tsunami every 800 years as powerful as the one that destroyed Alexandria in AD 365. Using radiocarbon dating techniques, simulations and computer models, the researchers recreated the ancient disaster in order to identify the responsible fault. "We are saying there is probably a repeat time of 800 years for this kind of earthquake," said Ms. Beth Shaw, an earthquake scientist at the University of Cambridge, who led the study. Scientists study past earthquakes in order to determine the future possibility of similar large shocks. Identifying the fault for the AD 365 earthquake and tsunami is important for the tens of millions of people in the region, Ms. Shaw said. The fault close to the southwest coast of Crete last produced a big enough quake to generate a tsunami about 1300, which means the next powerful one could come in the next 100 years, she added in a telephone interview. Ms. Shaw and her colleagues calculate the likely intervals by measuring the motion of either side of the fault to find how often such large earthquakes would have to occur to account for that level of motion, she said. Their computer model suggested an 8 magnitude quake on the fault would produce a tsunami that floods the coastal regions of Alexandria and North Africa, the southern coast of Greece and Sicily all the way up the Adriati to Duhrovnik. This would be similar to the ancient quake in AD 365 that caused widespread destruction in much of Greece and unleashed a tsunami that flooded Alexandria and the Nile Delta, likely killing tens of thousands of people, she said.

单选题It was difficult to see ships in the distance because of the fog .

单选题A whale shark"s body is stout but streamlined, like that of a whale.

单选题For some obscure reason, the simple game is becoming very popular.A. obviousB. majorC. unclearD. minor

单选题She came across three children sleeping under a bridge.

单选题Mary McCarthy's satires are couched in a prose style that has a classic precision.

单选题Rockets in the Sky If someone asked you. "What color is the sky?" I expect that you would answer, "Blue." I am afraid that you would be wrong. The sky has no color. When we see blue, we are looking at blue sunlight. The sunlight is shining on little bits of dust in the air. We know that there is air all around the world. We could not breathe without air. Airplanes could not fly without air. They need air to lift their wings. Airplanes cannot fly very high because as they go higher the air gets thinner. If we go far enough away from the earth, we find there is no air. What is the sky? The sky is space. In this space there is nothing except the sun, the moon and all the stars. Scientists have always wanted to know more about the other worlds in the space. They have looked at them through telescopes and in this way they have found out a great deal. The moon is about 384,000 kilometers away from the earth. An airplane cannot fly to the moon but there is a thing that can fly even when there is no air. This is rocket. I am sure that you are asking. "How does a rocket fly?" If you want to know, get a balloon and then blow it up until it is quite big. Do not tie up the neck of the balloon. Let go! The balloon will fly off through the air very quickly. The air inside the balloon tries to get out. It rushes out through neck of the ball off and this pushes the balloon through the air. It does not need wings like an air plane. This is how a rocket works. It is not made of rubber like a balloon, of course. It is made of metal. The metal must not be heavy but it must be very strong. There is gas inside the rocket which is made very hot. When it rushes out of the end of the rocket, the rocket is pushed up into the air. Rockets can fly far out into space. Rockets with men inside them have already reached the moon. Several rockets, without men inside them, have been sent to other worlds much farther away. One day rockets may be able to go anywhere in the space.

单选题The graduate students will convene in the Student Union. A. converse B. meet C. summon D. raze

单选题Can Buildings Be Designed to Resist Terrorist Attack? In the aftermath of the terrorist attack on the World Trade Center, structural engineers are trying hard to solve a question that a month ago would have been completely unthinkable: Can buildings be designed to withstand catastrophic blasts (爆炸) inflicted by terrorists? Ten days after the terrorist attacks on the twin towers, structural engineers from the University at Buffalo and the Multidisciplinary Center for Earthquake Engineering Research (MCEER) headquartered (总部在某地) at UB traveled to ground zero as part of a project funded by the National Science Foundation. Visiting the site as part of an MCEER reconnaissance (事先考查) visit, they spent two days beginning the task of formulating ideas about how to design such structures and to search for clues on how to do so in buildings that were damaged but still are standing. "Our objective in visiting ground zero was to go and look at the buildings surrounding the World Trade Center, those buildings that are still standing, but that sustained damage," said M. Bruneau, Ph.D. "Our immediate hope is that we can develop a better understanding as to why those buildings remain standing, while our long-term goal is to see whether earthquake engineering technologies can be married to existing technologies to achieve enhanced performance of buildings in the event of terrorist attacks," he added. Photographs taken by the investigators demonstrate in startling (惊人的) detail the monumental damage inflicted on the World Trade Center towers and buildings in the vicinity. One building a block away from the towers remains standing, but was badly damaged. "This building is many meters away from the World Trade Center and yet we see a column there that used to be part of that building," explained A. Whittaker, Ph. D. "The column became a missile that shot across the road, through the window and through the floor." The visit to the area also revealed some surprises, according to the engineers. For example, the floor framing system in one of the adjacent buildings was quite rugged, allowing floors that were pierced by tons of falling debris to remain intact. "Highly redundant ductile (有延展性的) framing systems may provide a simple, but robust strategy for blast resistance," he added. Other strategies may include providing alternate paths for gravity loads in the event that a load-bearing column fails. "We also need a better understanding of the mechanism of collapse," said A. Whittaker. "We need to find out what causes a building to collapse and how you can predict it." A. Reinhorn, Ph. D. noted that "Earthquake shaking has led to the collapse of many buildings in the past. It induces dynamic response and extremely high stresses and deformations in structural components. Solutions developed for earthquake-resistant design may be directly applicable to blast engineering and terrorist-resistant design. Part of our mission now at UB is to transfer these solutions and to develop new ones where none exist at present."