听力材料

Task 4Drill #1 Heart Valve ReplacementPeople with defective（有缺陷的）heart valves need them replaced, and what’s often used is the heart valve from a pig. It’s called a “porcine valve” because of that: A pig’s valve is very similar to a person’s, and because pig valves are natural and tend to be accepted by the body, patients who receive them require little treatment after surgery…relatively, for transplant（器官移植）patients, I mean. Now, there are problems. For example, pig valves tend to last around ten years---not very long.Actually, now that I’m on that topic, I might mention that porcine valves are not the only option. Alternative valves have been developed that are entirely artificial.They’re made of plastic and metal. These valves can last for decades---certainly a lot longer than pig valves. But the human body recognizes that plastic and metal are artificial. So what happens is that blood sticks to them, and blood clots（血凝块）form around them. These clots are dangerous because they can block the flow of blood. For that reason, patients who receive artificial valves spend the rest of their lives taking drugs that prevent blood from clotting. The drugs can be tough for the body tohandle, but they’re worth it for the sake of having a functioning heart valve.Drill #2 Birds of Prey（捕食，掠食）There are two bird species found in our local area that I think do a good job of exemplifying the range of ways birds of prey can adapt. One is the bald eagle, and the other is the great blue heron（鹭）. They both feed largely on fish, and they’re both large. But the more closely you observe them, the more the differences show.The bald eagle is always on the lookout（警戒）for dead fish at the side of river or lake or for fish that it can grab from close to the surface of the water. That’s because it has very sharp eyesight and strong talons. It can swoop（俯冲）down, grab a fish in its claws, and start eating it midair,food into its mouth.The great blue heron might eat those same fish, but it would have to go about it differently. The heron does have good eyesight----it’d be hard to see prey otherwise, right? Butits claws aren’t as strong as the eagle’s, so it usually attacks by diving into the water head-first. The heron has a long, straight beak that it can use either like a spear（矛，枪，鱼叉）to impale（钉在……上）a fish or like tongs（V形夹子）to grab it.Drill #3 BehaviorismOne of the earliest behaviorists is Ivan Pavlov, an experimental psychologist noted for his studies of the reflex reaction in humans and animals. A reflex is an involuntary（无意识做出的）action of the body, such as a sneeze, a blink, or a hiccup（打嗝）. Pavlov did a series of experiments using dogs. He found that when a bell is rung each time a dog is fed, the dog starts to associate the sound of the bell with food. Consequently, whenever the bell rings, the dog expects food. The dog salivates（分泌唾液）and drools（流口水）,and there is an increase in the flow of this stomach juices. The dog’s bodily response to the bell is a conditioned reflex, a behavior that occurs because the dog has been trained by the sound of the bell.Pavlov’s experiments with dogs and discovery of the conditioned reflex contributed to the development of behaviorism. The dog’s bodily response---- its behavior ---- does not come from something inside he dog. Rather, the behavior is the result of conditioning, the careful control of the dog’s environment. Pavlov argued that the dog’s behavior ---- drooling ---- was strictly a reaction to the environmental stimulus of the bell.Drill #4 Work and Family RolesNot surprisingly, women report more conflict between work and family roles. Women who work outside the home actually put in more hours of work at home. Women do more of the childcare and housework than their husbands do, whether the woman works full-time or not. Women are much more likely to leave the workforce entirely when their children are young. They’re also more likely to stay home with a sick child or to be the one to rearrange their work schedule to go to a meeting at the child’s school. They’re more likely to feel overworked and stressed-out.For most men, including men who are highly successful in their careers, family is far more important than work for their overall life satisfaction. The roles of husband and father are central to a man’s mental and physical health. So it’s not surprising that men carry emotional distress from the family into the workplace, even though they don’t experience the same degree of role conflict or overload as women do. In one study of working men and women, men more often than women reported that an argument at home was followed by higher rates of argument with coworkers or supervisors at work the next day.The same study reported that when the man came home overly tired from work, the wives did more of the work at home. The reverse pattern occurred less often: the husband did not do more of the work at home after his wife had had an especially hard day at work.Task 6Drill #1All foods will eventually spoil（v.变质）if they’re not preserved. Food preservation is the process of preventing or slowing the natural decay（v. & n.腐烂）of edible plants and animals, spoilage（n.腐败，损坏）that results from microorganisms（微生物）– bacteria, molds（霉菌）, and yeasts （酵母，发酵物）– that are present in the food.The most natural method of preserving food is drying. Nature preserves the seeds for next year’s crop by drying the outer layers of fruits and vegetables that are exposed to the sun and air. We copy nature’s effects by exposing food to warm air, a method that removes all the water that would otherwise lead to spoilage. Microorganisms need moisture（水分，水汽）to grow, so removing the water will stop the microorganisms from growing.Drying is a very ancient form of food preservation. Prehistoric （史前的）people dried grains, fruits, and nuts in the sun. When fire was discovered, they learned to smoke meat and fish by the fireside. Native Americans dried and chopped （剁，砍）meat, then mixed it with fat. The lack of moisture in the meat kept it from spoiling. Modern industrial science hasperfected the techniques of drying and applied them to the mass production of a variety of foods, such as powdered eggs and milk, peas, mushrooms, coffee, soups, and salad dressings.Another method of food preservation is curing（食物加工法）. Curing is done by adding ingredients（佐料，配料）, such as salt, sugar, spices, or lemon juice. Curing is one of the oldest methods of food preservation and is still used in the production of many meats and fish. The ingredients used in curing have unique reactions with the food they’re added to. For example, salt slows the growth of microorganisms and removes some of the water from the food. Sugar counteracts （对抗，抵消）the hardening（潮解）that’s sometimes caused by salt. Lemon or lime（酸橙汁）juice added to raw（生的，未加工的）fish will preserve the fish for a short time without removing all the moisture.Drill #2Although cities have not generally been associated with wildlife, there are many species that have become so much apart of the urban landscape that they are, for the most part, unnoticed neighbors. For example, in New York’s Central Park, almost 300 species of birds have been identified. Urban parks certainly provide some of the world’s safest and in many ways, best wildlife habitats, and as the natural habitats shrink, well, these urban parks will become more and more important to the conservation of wildlife, including not only birds…but, uh…but also freshwater animals and, even small mammals. So, as you see, man-made areas are one important type of habitat in cities.in the urban landscape…these can also provide a home for animals that adapt to life in the city. For instance, chimney swifts（北美洲产的燕子）are birds that originally lived in hollow trees, but now chimney swifts are commonly found in the long brick chimneys in factories or other vertical shafts（耸立的直筒）in tall buildings. Think about it. A city has more chimneys than there are hollow trees in a forest of equal area. Consequently, these birds flock（成群结队地飞向）to the city. Another case of adaptation is the urban drainage（排水，排水系统）system, which is usually made up of concrete ditches（沟，渠）, and they naturally attract stream and marsh（沼泽）animals. Again, to use New York City as anexample, probably 250 species of fish are found in the harbor （海港）, many of which make their way into the pools and ponds and ditches in the New York drainage system. In Boston, the Back Bay was actually designed to create habitats and attract marshland wildlife to the city.Drill #3Okay, as you’ll recall, caves form in limestone（石灰岩）when acidic（酸性的）groundwater follows some kind of weakness in the rocks. Now the rock formations（岩层）in a cavern…that’s the technical name that we use for a cave…the rock formations there are of two kinds…stalactites（钟乳石）and stalagmites（石笋）. Both of these formations are water that contains dissolved（可溶解的）minerals that… that accumulate and build deposits（沉淀物）. But stalactites hang down from the ceiling of the cavern, and stalagmites protrude（使伸出，突出）up from the floor of the cavern.Well, these words sound a lot alike, and this can be confusing, so I always tell my students to remember that there is a t in stalactites, and the t has a tail that hangs down just likethe stalactites that hang down from the ceiling of the cave, but there is an m in stalagmites and the points on an m stick up（竖起）like the stalagmites that protrude up from the ground in a cave. And if that doesn’t work for you, another way to remember the difference is that stalactite has a c in it, and so does the word ceiling, whereas stalagmite has a g in it, and so does the word ground. So stalactites drip down（滴下）from the ceiling and stalagmites build up from the ground. So with these little tricks for remembering the difference, I expect you all to get this right on the next quiz.Drill #4A major study shows that the world’s oceans face several serious problems related to overfishing, pollution, climate change, and loss of habitat.At least one-third of the fish stocks（家世，家系，血统）are “overfished”. This includes several groundfish species that will take decades to recover. The estimated number of large ocean predators（捕食性鱼类）----tuna, marlin, sharks, and halibut（大比目鱼）----has fallen 90 percent globally in half acentury. One reason for overfishing is bottom trawling（拖网捕鱼）the practice（n.常规，惯例）of dragging nets along the sea bottom to catch huge quantities of fish. Bottom fishing with nets can destroy habitat and contribute to fish declines.Pollution is a serious and growing danger. Land-based pollution in the form of erosion puts silt（淤泥）into the ocean, killing marine life close to shores. Cargo ships, container ships, and cruise（乘船游览）ships dump（倾倒）at least 65 million gallons of petroleum products a year into the seas. Even small amounts of oil can damage sensitive marine environments. Scientists estimate that nearly 30 million gallons of petroleum seep（液体渗透）into North American waters every year, most of it from runoff, seaplanes, and small boats.Climate change is causing new disease outbreaks（爆发，突然发生）in ocean environments, affecting everything from coral reefs to oysters（牡蛎）. Diseases threaten many corals in the Pacific. Since coral reefs provide rich habitat for fish, the loss of coral contributes to fish declines. Climate change also hurts large mammals that depend on fish. In the Arctic, melting ice may be preventing polar bears from reaching their fishing areas, and this affects their breeding patterns and thesurvival of their young cubs（幼小的兽）.1. green grain2. warm worm3. wonder wander4. fear fair fire (on fire unfair)5. east yeast/i:st/ /ji:st/6. horse house1. grad=graduation2. math(s)=3. P.E.=phys.ed.=4. intro=5. dorm=6. gym=gymnasium Thesis dissertationL.A. /el/ /ei/L m n o p w /el/ /em/ /en/ //Task 61. listen to a lecture: 1 professor,1.5~2 mins2. 准备：20 s3. 答题: 60 s特点：1. 词汇 2. 信息量 3. 句式/语法策略：1. 背单词 2. 笔记量 3. 二次重复 4. 重读、停顿 5. 结构词：核心：1+2答题：1. 时间 2. 句式：。