单选题Public lands can be used for energy development when

单选题Scientists Make Sweet Discovering Good news for chocoholics: the treat preferred by millions all over the world is good for you, according to American researchers at the University of California. Chocolate contains substances called flavonoids that can help maintain a healthy heart and good circulation. The researchers have discovered that cocoa acts like aspirin and that eating a bar of chocolate has also been shown to release endorphins in the body: these chemicals help to reduce pain and stress and make you feel happy. The Olmec Indians of Mexico and Central America were the first to grow cocoa beans, in about1500 BC, and the Mayas were drinking unsweetened coca hundreds of years before it became fashionable in Europe. In 1544, a delegation of Mayan nobles visited Philip of Spain and gave him jars of cocpa as a gift. Cocoa soon became fashionable in Spain and Portugal. The Spanish were the first to add sugar to their cocoa drink. By the middle of the century, solid chocolate was becoming familiar. In 1765, James Baker and John Hanan opened the first chocolate mill in the United States, introducing chocolate to the average citizen. In 1896, in Switzerland, Daniel Peter had the idea of adding milk in the chocolate-making process and produced the first milk chocolate. Since then, chocolate has grown enormously in popularity. One of the biggest chocolate-eating nations is Britain where the average man, women, and child eats nine kilos of chocolate a year. In fact, chocolate is the number one comfort food and there are more chocoholics in Britain than any where else in the world. Researchers warn that although chocolate is good for you, it should be eaten in small quantities and with no added milk.

单选题When I heard the noise in the next room, I couldn’t resist having a (peep) look.A. chance B. visit C. look D. try

单选题We have never seen such gorgeous hills.

单选题What does Moravec think of these future robots?

单选题The economy continued to exhibit signs of decline in September.

单选题 Green Roof Research The concept of green roofs is basically about growing plants on roofs, thus helping to replace the green footprint that had been destroyed due to the construction of the building. Green roofs are the most prevalent (流行) in Germany, which is widely regarded as the leader in green roof research. The green roofs that are used these days can be classified as "extensive" and "intensive" systems. Extensive green roofs use mosses, grasses and herbs, which are tolerant to droughts. These plants do not need much maintenance, can be grown in a layer of substrate (土层) that can be as shallow as 1.5 inches, and generally are inaccessible to the public. In contrast, a wide range of species of plants are grown on intensive green roofs, such as shrubs (灌木) and even trees, which require deeper substrate layers, and are usually grown on flat roofs. They need intensive maintenance, and are usually areas that resemble parks which are accessible to people. There are several benefits of adopting green roof technologies. Apart from the obvious psychological and aesthetic (审美学的) benefits of garden—like environments surrounding you, some of the common economic and ecological benefits are: a reduction in the consumption of energy; air and water purification; recovering green spaces; and the mitigation (缓解) of the heat island effect in urban areas. The green roof research that is currently ongoing is focused on evaluating the species of plants that are suitable to be grown on roofs, the methods of propagation (繁殖) as well as establishment, nutrient (养料) and water requirement, substrates, and the quantity and quality of water runoff. The evaluation criteria of plant species are: at what rate they can be established their capacity to withstand invasive weeds; tolerance of cold and heat; tolerance of drought conditions; capacity of persistence and survival. A number of experiments are being conducted on roof platform simulations at various research centers. These sites are generally outfitted with equipment, which are used to measure temperatures at different depths of the growing substrates, and the rate and volume of the runoff of stormwaters from each of the platforms. Green roof technology is representative of a completely new market for landscape contractors, and all roofs that currently exist and the future ones to be constructed are the potential market—a market that is too huge to be overlooked.

单选题We have got to abide by the rules.

单选题Nowadays nearly everyone has suffered from a bad attack of forgetfulness when a password is needed. The company computer, the home computer, banking and ATM machines, Websites, car and home security systems. The list goes on. It does not take long to accumulate a dozen or more passwords. Scribbling them down on slips of paper or simply using the same password for anything and everything is how most people cope with the overload. The negative aspect of this is that either way makes it easier for hackers to invade computer privacy. Using the same password for everything may result inA. the user's forgetfulness.B. the user's overload.C. the loss of banking accounts.D. the theft of privacy.

单选题第一篇 Pool Watch Swimmers can drown in busy swimming pools when lifeguards fail to notice that they are in trouble. The Royal Society for the Prevention of Accidents says that on average 15 people drown in British pools each year, but many more suffer major injury after getting into difficulties. Now a French company has developed an artificial intelligence system called Poseidon that sounds the alarm when it sees someone in danger of drowning. When a swimmer sinks towards the bottom of the pool, the new system sends an alarm signal to a poolside monitoring station and a lifeguard"s pager. In trials at a pool in Ancenis, near Nantes, it saved a life within just a few months, says Alistair McQuade, a spokesman for its maker, Poseidon Technologies. Poseidon keeps watch through a network of underwater and overheard video cameras. AI software analyses the images to work out swimmers trajectories. To do this reliably, it has to tell the difference between a swimmer and the shadow of someone being cast onto the bottom or side of the pool. "The underwater environment is a very dynamic one, with many shadows and reflections dancing around." says McQuade. The software does this by "projecting" a shape in its field of view onto an image of the far wall of the pool. It does the same with an image from another camera viewing the shape from a different angle. If the two projections are in the same position, the shape is identified as a shadow and is ignored. But if they are different, the shape is a swimmer and so the system follows its trajectory. To pick out potential drowning victims, anyone in the water who starts to descend slowly is added to the software"s "pre-alert" list, says McQuade. Swimmers who then stay immobile on the pool bottom for 5 seconds or more are considered in danger of drowning. Poseidon double-checks that the image really is of a swimmer, not a shadow, by seeing whether it obscures the pool"s floor texture when viewed from overhead. If so, it alerts the lifeguard, showing the swimmer"s location on a poolside screen. The first full-scale Poseidon system will be officially opened next week at a pool in High Wycombe, Buckinghamshire. One man who is impressed with the idea is Travor Baylis, inventor of the clockwork radio. Baylis runs a company that installs swimming pools, and he was once an underwater escapologist with a circus. "I say full marks to them if this works and can save lives," he says. But he adds that any local authority spending ￡30,000-plus on a Poseidon system ought to be investing similar amounts in teaching children to swim.

单选题In some cases managers have to learn how to write programs so as to work out computerized information systems that suit their own companies best.

单选题The Need to Remember Some people say they have no memory at all: "I just can't remember a thing!" But of course we all have a memory. Our memory tells us who we are. Our memory helps us to make use in the present of what we have learnt in the past. In fact we have different types of memory, For example, our visual memory helps us recall facts and places. Some people have such a strong visual memory, they can remember exactly what they have seen, for example, pages of a book, as a complete picture. Our verbal (言语的) memory helps us remember words and figures we may have heard but not seen or written: items of a shopping list, a chemical formula, dates, or a recipe. With our emotional (情感的) memory, we recall situations or places where we had strong feelings, perhaps of happiness or unhappiness. We also have special memories for smell, taste, touch and sound, and for performing physical movements. We have two ways of storing any of these memories. Our short-term memory stores items for up to thirty seconds - enough to remember a telephone number while we dial. Our long-term memory, on the other hand, may store items for a lifetime. Older people in fact have a much better long-term memory than short-term. They may forget what they have done only a few hours ago, but have the clearest remembrance (记忆) of when they were very young. Psychologists tell us that we only remember a few facts about our past, and that we invent the rest. It is as though we remember only the outline of a story. We then make up the details. We often do this in the way we want to remember them, usually so that we appear as the heroes of our own past - or maybe victims needing sympathy (同情).

单选题The most widely seen sculptural work clone by Augusta Savage was probably "Lift Every Voice and Sing" , shown at the 1939-1940 New York world's fair.

单选题Before the supper, my morn asked me to {{U}}lay{{/U}} the table.

单选题Japan made a proposal to Korea for increasing trade between two countries. A. preparation B. exception C. suggestion D. companion

单选题The conclusion can be {{U}}deduced{{/U}} from the premises.

单选题She stared at his son and shaked with anger.

单选题She was one of the Uleading/U writers of her day.

单选题His idea to solve the problem is really original .

单选题Her faith Uupheld/U her in times of sadness.