单选题We"ll do all we can to assist you.

单选题These programmes are of immense value to old people.

单选题Deforestation and Desertification(沙漠化) The Sahel zone lies between the Sahara desert and the fertile savannahs (热带大草原) of northern Nigeria and South Sudan. The word sahel comes from Arabic and means marginal or transitional, and this is a good description of these semi-arid (半干旱) lands, which occupy much of the Western African countries of Mall, Mauritania, Niger, and Chad. Unfortunately, over the last century the Sahara desert has steadily crept southwards eating into once productive Sahel lands. United Nations surveys show that over 70 percent of the dry land in agriculture use in Africa has deteriorated over the last 30 years. Droughts have become more severe, the most recent lasting over twenty years in parts of the Sahel region. The same process of desertification is taking place across southern Africa as the Kalahari desert advances into Botswana and parts of South Africa. One of the major causes of this desert advance is poor agricultural land use, driven by the pressures of increasing population. Overgrazing—keeping too many farm animals on the land—means that grasses and other plants cannot recover, and scarce water supplies are exhausted. Overcultivation—trying to grow too many crops on poor land—results in the soil becoming even less fertile and drier, and beginning to break up. Soil erosion (侵蚀) follows, and the land turns into desert. Another cause of desertification is loss of tree cover. Trees are cut down for use as fuel and to clear land for agricultural use. Tree roots help to bind the soil together, to conserve moisture, and to provide a habitat for other plants and animals. When trees are cut down, the soil begins to dry and loosen, wind and rain erosion increase, other plant species die, and eventually the fertile topsoil may be almost entirely lost, leaving only bare rock and dust. The effects of loss of topsoil and increased drought are irreversible. They are, however, preventable. Careful conservation of tree cover and sustainable agricultural land use have been shown to halt deterioration of soils and lessen the effects of shortage of rainfall. One project in Kita in south-west Mall funded by UNDP has involved local communities in sustainable management of forest, while at the same time providing a viable (有活力的) agricultural economy. This may be a model for similar projects in other West African countries.

单选题We cannot compel you to do it, but we think you should.

单选题Coming Soon to a Theater near You! What are special effects? Do you enjoy movies that use a lot of special effects?. Dinosaurs (恐龙) from the distant past! Space battles from the distant future! There has been a revolution in special effects, and it has transformed the movies we see. The revolution began in the mid-1970s with George Lucas's Star Wars, a film that stunned (使震惊) audiences. That revolution continues to the present with dramatic changes in special effects technology. The company behind these changes is Lucas's Industrial Light ＆ Magic (ILM). And the man behind the company is Dennis Muren, who has worked with Lucas since Star Wars. Muren's interest in special effects began very early. At the age of 6, he was photographing toy dinosaurs and spaceships. At 10, he had an 8 millimeter movie camera and was making these things move through stop motion. (Stop-motion is a process in which objects are shot with a camera, moved slightly, shot again, and so on. When the shots are put together, the objects appear to move.) Talk to Muren and you'll understand what ILM is all about; taking on new challenges. By 1989, Muren decided he had pushed the old technology as far as it would go. He saw computer graphics(图像)(CG)technology as the wave of the future and took a year off the master it. With CG technology, images can be scanned into a computer for processing, for example, and many separate shots can be combined into a single image. CG technology has now reached the point, Muren says, where special effects can be used to do just about anything so that movies can tell stories better than ever before. The huge success of Jurassic Park and its sequel (续集), The Lost World, the stars of which were computer-generated dinosaurs, suggests that this may very well be true.

单选题During the 1800's and early 1900's, new academic disciplines such as chemistry and physics made great {{U}}headway{{/U}}.

单选题He"s going to set off on a journey to New York.

单选题These programs are of {{U}}immense{{/U}} value to old people. A. natural B. fatal C. tiny D. enormous

单选题Mr. Henley has accelerated his sale of shares over the past year. A. held B. increased C. expected D. offered

单选题Data from Voyager II have presented astronomers with a puzzle about why our outermost planet exists. A. problem B. mystery C. question D. point

单选题The program, run by psychotherapists Cosette Dawna Rae and Hilarie Cash, is located in Rae's house, where her husband and son also reside. There's room for six patients, but during Alexander's treatment, he is the only one at the facility. He is given a regular schedule, with outdoor activities (including carpentry projects or caring for chickens and goats) plotted throughout the day, plus chores and meals. Rae says the program is designed to mimic what life will be like once patients return home--downtime is built into the routine, so people can learn to cope with boredom. Alexander spends some of that time running--when he first got to the facility, he expressed all interest in running, so Rae and Cash set him up with a local trainer, who now takes him on regular jogs. Alexander also has daily counseling sessions with Rae ,where they discuss his long- term goals, and even work on a plan for a tutoring business he hopes to start. Once a week, he has a therapy session with Cash, a specialist in video game and Internet addiction. Downtime was built into the routine during whichA. Alexander read his favorite book.B. Alexander learned to deal with boredom.C. Alexander rested to recover from fatigue.D. Alexander started to think about his futur

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。 Street sellers particularly in developing countries, supply large amounts of food{{U}} (51) {{/U}}people on low incomes. This sector also employs some 6%～25% of the work force, mainly women, in developing countries, and provides markets for agricultural and other produce. In many countries{{U}} (52) {{/U}}, the authorities are not willing to recognize it{{U}} (53) {{/U}}a formal sector of the food supply system, they may ignore it in food control programs or even try to put an end to{{U}} (54) {{/U}}. There are tow possible contaminants: pathogenic micro-organisms;{{U}} (55) {{/U}}hazardous chemicals: As{{U}} (56) {{/U}}as micro-organisms are concerned, there is apparently no convincing evidence that street foods are more involved in the transmission of infection{{U}} (57) {{/U}}foods obtained in, e. g. hotels. Studies in Egypt and else- where have found street foods to compare not unfavorably with hotel{{U}} (58) {{/U}}in respect of contamination with micro-organisms--some street foods were found to be contaminated with pathogens, but so also were foods from four-and five-star{{U}} (59) {{/U}}in the same area. Hazardous chemicals have{{U}} (60) {{/U}}found in street foods, and food exposed for sale on roadsides may become contaminated by lead from vehicle exhausts. Health dangers may arise{{U}} (61) {{/U}}purchase of raw food of poor quality; improper storage, processing, and cooking, leading to reuse of water; limited piped drinking water; lack{{U}} (62) {{/U}}refrigeration; and unsatisfactory waste-disposal facilities; inexperienced or personal cleanliness. The authorities should take{{U}} (63) {{/U}} account the potentials of different categories of food for transmitting disease, and should control appropriately for the different{{U}} (64) {{/U}}-sellers of bottled drinks require less control than those of food. Dry foodstuff, dried grains, and sugared foods are less likely to transmit disease than gravies, cooked rice, and low-acid milk, egg, and meat products. Similarly foods which are thoroughly cooked and eaten at{{U}} (65) {{/U}} are safer than precooked food kept at high temperatures for several hours.

单选题The police believe theU motiv/U e for the murder was jealousy．

单选题His job was to look after the animals.

单选题Let's {{U}}set{{/U}} up a meeting with other parents, so everyone can learn ways to make water safer for our children to drink.

单选题The Spanish Flu Epidemic If you"re worried about the possibility of a coming bird flu epidemic, you can take comfort in the fact that humanity has survived a similar influenza epidemic in the past. Starting its rounds at the end of World War I, the 1918 flu killed an estimated 50 million people. Popularly known as the Spanish Flu, this type of influenza was far worse than your common cold. Normally, influenza only kills those who are more vulnerable to disease, such as newborns, the old or the sick. However, the Spanish Flu was prone to killing the young and healthy. Often it would disable its victims in hours; within a day, they would be dead, typically from extreme cases of pneumonia(肺炎). The Spanish Flu was quite nasty-fast-spreading and deadly. It managed to spread across the globe, devastating the world. Then suddenly, after two years ravaging(蹂躏)the Earth, it disappeared as quickly as it bad arisen. Despite its nickname, the Spanish Flu did not originate in Spain. Its true origins are unknown. Some believe it started in US forts and then spread to Europe as America joined the war; others think that it populated the trenches of the English and the French and eventually broke out in 1918. Regardless of where it started, eventually a fifth of the world population suffered the disease, with a global mortality rate(死亡率) estimated at 2.5% of the population. Modernity was partly to blame for the quick spread of the disease. It passed throughout the world on trade routes and shipping lines. It hit Northern America, Europe, Asia, Africa and the South Pacific. The war did not help at all—the movement of supplies and troops aided the spread of the Spanish Flu, as well as the trench warfare. Imagine the speed at which a virus can spread in a crowded ditch. The fast emergence of the virus in the trenches caused some soldiers to believe that the Spanish Flu was a new form of biological warfare. Luckily, the Spanish Flu simply vanished by 1920. It is believed the flu simply ran out of fuel to spread.

单选题The government is debating the education laws.

单选题There was a {{U}}simultaneous{{/U}} trial taking place in the next building. A. fair B. full C. public D. coexisting

单选题It is no use {{U}}debating{{/U}} the relative merits of this policy. A. making B. taking C. discussing D. expecting

单选题Fortunately, she managed to finish the work on time.A. HappilyB. LuckilyC. FranklyD. Honestly