单选题Writing is a skill that requires {{U}}consistent {{/U}}practice.

单选题 Obtaining Drinking Water from Air Humidity Not a plant to be seen, the desert ground is too dry. But the air contains water, and research scientists have found a {{U}} {{U}} 1 {{/U}} {{/U}}of obtaining drinking water from air humidity. The system is based completely on renewable energy and is therefore autonomous. Cracks permeate the dried-out desert ground and the landscape bears testimony to the lack of water. But even here, where there are no lakes, rivers or groundwater, considerable quantities of water are stored in the air. In the Negev desert in Israel, for example, annual average relative air humidity is 64 percent-in every cubic meter of air there are 11.5 milliliters of water. German research scientists have found a way of converting this air humidity autonomously into drinkable water. "The process we have developed is based exclusively on renewable energy sources {{U}} {{U}} 2 {{/U}} {{/U}}thermal solar collectors and photovoltaic ceils, {{U}} {{U}} 3 {{/U}} {{/U}}makes this method completely energy-autonomous. It will {{U}} {{U}} 4 {{/U}} {{/U}}function in regions where there is no electrical infrastructure." says Siegfried Egner, head of the research team. The principle of the {{U}} {{U}} 5 {{/U}} {{/U}}is as follows: hygroscopic brine-saline solution which absorbs moistureruns down a tower-shaped unit and absorbs water from the air. It is then sucked {{U}} {{U}} 6 {{/U}} {{/U}}a tank a few meters off the ground in which a vacuum prevails. Energy from solar collectors {{U}} {{U}} 7 {{/U}} {{/U}}up the brine, which his diluted by the water it has {{U}} {{U}} 8 {{/U}} {{/U}}. Because of the vacuum, the boiling point of the liquid is lower than it would be under {{U}} {{U}} 9 {{/U}} {{/U}}atmospheric pressure. This effect is known from the mountains: as the atmospheric pressure there is lower than in the valley, water boils at temperatures distinctly below 100℃. The evaporated, non-saline water is condensed and runs down through a completely filled tube in a controlled manner. The gravity of this water column {{U}} {{U}} 10 {{/U}} {{/U}}produces the vacuum and so a vacuum pump is not needed. The reconcentrated brine {{U}} {{U}} 11 {{/U}} {{/U}}down the tower surface again to absorb moisture from the air. "The concept is suitable for various water {{U}} {{U}} 12 {{/U}} {{/U}}. Single-person units and plants supplying water to entire hotels are conceivable, " says Egner. Prototypes have been built for {{U}} {{U}} 13 {{/U}} {{/U}}system components-air moisture absorption and vacuum evaporation-and the research scientists have already {{U}} {{U}} 14 {{/U}} {{/U}}their interplay on a laboratory scale. In a further {{U}} {{U}} 15 {{/U}} {{/U}}the researchers intend to develop a demonstration facility.

单选题We're happy to collaborate with you in the project. A. compete B. cooperate C. coordinate D. contend

单选题From my standpoint, this thing is just ridiculous A. field B. point of view C. knowledge D. information

单选题What is the writer’s attitude to robots in the future?

单选题His claims seem Ucredible/U to many people.

单选题The girl is {{U}}gazing{{/U}} at herself in the mirror.

单选题阅读下面的短文，文中有15处空白，每处空白给出4个选项，请根据短文的内容从4个选项中选择1个最佳答案。 Energy equals mass times the speed of light squared. This is the famous equation of Albert Einstein. It{{U}} (51) {{/U}}to the category of the theory of relativity, and it equates energy with mass. All things are made up of atoms. When{{U}} (52) {{/U}}of an atom travels at almost the speed of light{{U}} (53) {{/U}}we put more energy into it to increase the speed, it begins to in crease in mass. The energy that makes it travel fast cannot make it travel{{U}} (54) {{/U}}the speed of light—nothing{{U}} (55) {{/U}}light can travel that fast- so the energy goes into the thing{{U}} (56) {{/U}}and increases its mass. Energy{{U}} (57) {{/U}}into mass. Why is the theory called the theory of relativity? A thing that is relative depends upon{{U}} (58) {{/U}}else to identify it or to define it. In relativity theory we identify or define mass, time, and length{{U}} (59) {{/U}}to the speed of light. When something is at rest, it looks{{U}} (60) {{/U}}in length. However, when it travels at almost the speed of light, it becomes{{U}} (61) {{/U}}. Time also changes. However, the change in time is{{U}} (62) {{/U}}to the change in length. The length of a thing becomes short{{U}} (63) {{/U}}time becomes long. If you want to{{U}} (64) {{/U}}young, relative to a friend, take a trip in a spaceship that travels at{{U}} (65) {{/U}}the speed of light. And, although time and heartbeat seem ordinary to you in the spaceship, when you return, look at your friend; Relative to you, he or she is old.

单选题Birdsong A male zebra finch chirps away to himself. Suddenly he notices a female bird nearby. He realizes he has an audience and immediately changes his song. Can the female tell the difference in his performance? According to a new study, the female zebra finch knows. And she prefers the special trills he creates when he sings to her. A male zebra finch changes his song when singing to a female in ways that people can barely detect. But the female finch can tell the difference. Scientists had noticed slight variations in the songs of male zebra finches based on whether they were singing alone or whether there was a female (and potential mate) nearby. With an audience, the males sped up the pace of their songs and controlled the notes they used. For this study, researchers Sarah C. Woolley and Allison Doupe at the University of California, San Francisco decided to focus attention on the listening females, which have not been well studied in the past. In the study, Woolley and Doupe set up, a long cage with a sound speaker at each end. One broadcast the sound of a male zebra finch singing to himself, like someone singing in the shower. The other speaker broadcast a male performing for a female audience, as if he was giving a concert. Female birds were placed between the two speakers. Some of the birds had mates, others didn't. The females shifted around a bit, and then most of them hopped over to sit beside just one speaker. All the birds that made a clear choice liked songs meant for a female audience, even if they'd never met the male. Mated females also had a chance to listen to two different performance songs, one from an unknown male, and one from their mate. They spent more time listening to the concert version of their mates' songs. This suggests that after a while, females learn to recognize and prefer the songs of their mates. Scientists then studied the brains of the females. They found certain areas of the brain perked up when the birds listened to the concert songs. These brain areas may be involved in recognizing and evaluating the songs, and storing the memories of them. This research deals with what's called directed communication, when the communicator, or sender, focuses the message for a specific audience. One example is the way moms speak to their babies. Mothers around the world use the same sort of high-pitched sing-song chatter, and the babies respond best to those sounds. Songbirds are one of the only other species known to learn their communication, in this case their songs.

单选题A municipal management plan for storm-water runoff is mandated by the Clean Water Act. Early this year, Urban Stormwater Management in the United States, a report commissioned by the Environmental Protection Agency (EPA), recommended a number of ways to manage runoff, including using structural devices, like the kind AbTech produces. Rink is hoping that his merchandise appeals to budget-strapped municipalities. "Compared with building new storm-water treatment plants or upgrading already existing facilities to handle runoff pollution, which would cost in the millions of dollars, our products are very affordable," he says. The federal stimulus bill could make them even more so. AbTech products areA. structural devices.B. the best solution to run off.C. appealing to budget-strapped municipalities.D. costly.

单选题The role of women in Britain has changed a lot in this century, (51) in the last twenty years. The main change has been (52) giving women greater equality with men. Up to the beginning of this century, women seem to have had (53) rights. They could not vote and were kept at home. (54) , as far as we know, most women were happy with this situation. Today, women in Britain certainly (55) more fights than they used to. They were (56) the vote in 1919. In 1970 a law was passed to give them an equal (57) of wealth in the case of divorce, (58) the Equal Pay Act gave them the right of equal pay with men for work of equal value in the same year. Yet (59) these changes, there are still great difference in status between men and women. Many employers seem to (60) the Equal Pay Act, and the average working women is (61) to earn only about half that a man earns for the same job. (62) a survey, at present, only one-third of the country's workers are (63) women. This small percentage is partly (64) a shortage of nurseries. If there were (65) nurseries, twice as many women might well go out to work.

单选题Over the past two decades gee—engineering began to include other ways of fixing climate-including new spins on the Pinatubo effect. Using sulfur dioxide(二氧化硫) or other materials, they aim to reflect sunlight back into outer space. One would boost a series of mirrors into orbit, shading Earth from sunlight, but at a cost that would likely bankrupt the planet. In the 1990s, the controversial inventor of the hydrogen bomb, Edward Teller, proposed floating reflective particles of metal in the atmosphere, adding a Dr. Strangelove air to the gee-engineering field. Various kinds of materials are used in gee-engineering toA. bankrupt the earth.B. reflect sunlight back into space.C. boost mirrors into orbit.D. make hydrogen bombs.

单选题High pay may enhance productivity.A. confirmB. improveC. determineD. supplement

单选题The novel depicts the history of the nation.

单选题Ambition is a {{U}}characteristic{{/U}} of all successful businessmen.

单选题No civilized country should deem theft lawful .

单选题Tech Addiction" Harms Learning" The study of 267 pupils aged 11 to 18 found 63% felt addicted to the internet-Techno Addicts: Young Person Addiction to Technology-was carried out by researchers at Cranfield School of Management, Northampton Business School and academic consultancy AJM Associates. Researchers used a written questionnaire to examine the nature and the volume of mobile phone calls and text messaging as well as computer use including e-mail, instant messaging and accessing social networking sites. They found 62% first used or owned a computer before the age of eight, 80% first used the internet between the ages of five and 10,58% first used a mobile phone between the ages of eight and 10 and 58% have had access to a social networking sites between the ages of eleven and 13. Over 63% felt addicted to the internet. Over 30% reported spending between one to two hours a day using the internet and 26% said they spent up to six or more hours a day. On average, pupils said they spent between one and two hours on social networking sites each day. Over one in five(20.2%) said they left the phone on in lessons-which is usually forbidden by schools. Over a third(39%)admitted that text shortcuts damaged the quality of their written English, particularly when it came to spelling. And 84% openly admitted copying chunks of information from the internet into their homework or projects on a number of occasions. Dr Nada Kakabadse from Northampton Business School said modern technology, such as mobile phones and handheld computer games, was having an impact on pupils' attention levels. "They are hiding these things under the desks so their concentration cannot be equally divided, they are not focusing on what's going on in class. " Dr Kakabadse said pupils were also getting into a bad habit of plagiarism. "For their homework, instead of reading the book, they go on the internet and lift it. " She also raised concerns about the text-messaging abbreviations to which young people had grown accustomed. They have invented a new language. This kind of abbreviation they unconsciously bring into their assignments.

单选题 阅读下面的短文，文中有15处空白，每处空白给出了4个选项，请根据短文的内容从 4个选项中选择1个最佳答案。 {{B}}Unpopular Subjects?{{/B}} Is there a place in today's society for the study of useless subjects in our universities? Just over 100 years ago Fitzgerald argued in a well-written letter{{U}} (51) {{/U}} Nature that "Universities must be allowed to study useless subjects--{{U}} (52) {{/U}} they don't, who will?" He went on to use the{{U}} (53) {{/U}}of Maxwell's electrodynamics (电动力学) as one case where a "useless subject" has been transformed to a useful subject. Nowadays this argument is again very much{{U}} (54) {{/U}}in many universities. Indeed one suspects that it is one of those arguments that must be{{U}} (55) {{/U}} anew (重新) by each generation. But now there is an added twist (歪曲)--subjects must not only be useful, they must also be{{U}} (56) {{/U}}enough that students will flock (蜂拥) to do them, and even flock to pay to do them. As universities become commercial operations, the pressure to{{U}} (57) {{/U}} subjects or departments that are less popular will become stronger and stronger. Perhaps this is most strongly{{U}} (58) {{/U}}at the moment by physics. There has been much{{U}} (59) {{/U}}in the press of universities that are closing down physics departments and incorporate them with mathematics or engineering departments. Many scientists think otherwise. They see physics as a{{U}} (60) {{/U}}science, which must be kept alive if only to{{U}} (61) {{/U}}a base for other sciences and engineering. It is of their great personal concern that physics teaching and research is under{{U}} (62) {{/U}}in many universities. How can it be preserved in the rush towards commercial competition? A major turnaround (转变) in student popularity may have to{{U}} (63) {{/U}}until the industrial world discovers that it needs physicists and starts paying them well. Physics is now not only unpopular; it is also "hard". We can de more about the latter by{{U}} (64) {{/U}}teaching in our schools and universities. We can also{{U}} (65) {{/U}} cooperative arrangements to ensure that physicists keep their research and teaching up to date.

单选题After fossil fuels are used up, global warming will continue for ________

单选题Brilliantly colored flowers attract insects.