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在许多国家，草莓是一种重要的园艺作物。由于真菌病害严重影响其产量，对其进行防控，就带来使用过量化学物质的问题。尽管草莓抗病的分子标记已有报道，但是商业种植的草莓在遗传组成上是八倍体，所以难以将分子标记与抗病基因联系在一起。目前还没有有关从草莓中克隆可能的抗性基因的任何报道。本研究的目的是从野生和栽培的草莓中分离并鉴定抗性基因类似物（resistance gene analogues, RGAs），并对其变异性和系统进化关系进行评价。

The plant hormone abscisic acid (ABA) regulates interacting signaling pathways involved in plant responses to several abiotic stresses, such as drought, salt, and cold, as well as plant growth and development. The ABA-dependent signaling pathway regulates stress-inducible gene expression through several positive and negative regulators. Genetic analysis of Arabidopsis mutants compromised in ABA biosynthesis or signaling has identified a complex interplay between ABA and various other phytohormone signaling pathways. One of the relatively better characterized genetic interactions occurs among ABA, ethylene, and the sugar signaling pathways. Genetic analyses have also demonstrated that the ABA signaling pathway interacts antagonistically with the ethylene signaling pathway and vice versa to modulate plant development. (该短文引自：The Plant Cell 16:3460) (8分)

The interaction between transcription factors and cis-acting regulatory sequences presented in plant promoters is a key step involved in the regulation of plant gene expression. As a result, much effort has been made to dissect various plant promoters, to identify different transcription factors, and to study their specific interactions. Commonly, in vivo characterization of plant promoters and transcription factors is carried out by generation and analysis of transgenic plants expressing promoter/reporter gene fusion and/or corresponding trans-factors. This process is labor-intensive, time-consuming, and usually takes several months. In addition, transgene expression in transgenic plants often varies significantly due to insert position and other effects, thus complicating data analysis. To overcome some of those disadvantages, methods for transient expression analysis have been developed as convenient alternatives to stable transformation (该短文引自：The Plant Journal, 26: 543).

The ASR proteins, which are induced by abscisic acid (ABA), stress, and ripening, were first described in tomato. They are characterized as small, basic proteins with strong hydrophilicity as a result of high levels of His, Glu, and Lys. Subcellular fractionation experiments and immunodetection in tomato fruit chromatin fractions suggested that tomato ASRI is localized to the nucleus. This conclusion agrees with the fact that loblolly pine (火炬松) and melon ASR possess a putative nuclear targeting signal at the C terminus. Moreover, these nuclear basic proteins can bind DNA, as demonstrated by DNA gel blot and filter binding experiments for tomato ASR1. These data support the idea that ASRs resemble eukaryotic nonhistone chromosomal proteins (该短文引自：The Plant Cell, 15: 2165)

Directions: For this part, you are asked to write a composition on a certain topic. You should write at least 150 words and you should base your composition on the outline below:Owing a Car in Big Cities1.随着生活水平的提高，在大城市里有越来越多的人开始拥有汽车。2.拥有汽车的好处。3.拥有汽车可能带来的问题。

American astronomers high in the mountains of Puerto Rico have been trying to fathom the puzzle of the mysterious “pulsars” of deep space. These strange new signals were first picked up in 1967 on British radio telescopes. The signals originate from fifty to three hundred light years away, yet they always arrive at precise time intervals.Four pulsars have been located in a corner of our galaxy. And astronomers continue to look, or in this case, listen, since the pulsars are so far away that they cannot be detected by optical telescopes. The head of Cornell’s observatory in Puerto Rico says the energy used for these pulses is ten billion times greater than all the combined energy on earth.Several theories explaining the timed pulses have been offered. Most astronomers seem to believe these signals are a natural phenomenon. One idea is that a neutron star may be responsible. This is a star much like our sun, whose internal source of energy has burned out, causing it to collapse into mass of tremendous density.Another theory holds that some intelligent outer space civilization is producing the signals. There are strong arguments against that because pulsar energy seems wasted and the signals are spread over such a wide frequency range. Still another theory is that the signals come from stars that are invisible because civilizations that depend on them have built protective shells around them to conserve their energies.

There can be no doubt that sharks hear perfectly. Experience has shown that they react to the sound of blows under water, to the sound of a bell, or to the noises made by a diver at work. In general, their reaction is one of intense interest. I have often tried bits of advice like “If you see a shark approaching, beat the water with your hands,” or the famous warning given to beginning divers, “If you want to drive a shark away, cry out in the water.” In my experience, such advice is almost criminal. In most cases the consequence was an immediate attack.There seems to be no reason for the shark’s frenzy. This, I think, is what hits me most, giving me a feeling of complete helplessness. The mad rush of hordes of sharks toward the exact point where one of their own has devoured a bit of fish is terrifying to watch. The beasts seem unstoppable and fatal—and totally senseless.Sometimes the shark will flee from a naked and unarmed diver, and at other times he will throw himself against a steel diving cage and hit furiously at the vars. With any other animal—be it dog or crow—I know that my actions or reactions will have a direct influence on its behavior. But the shark moves through my world like a puppet whose strings are controlled by something other than the power moving mine; he seems to come from another planet. In fact, he does come from another time in that he has evolved little since his beginning. He perfectly adapts to his life, yet no one can ever predict what he will do.We do not know if sharks migrate from one region to another, but it has been established that the majority swim unceasingly, day and night. There are two reasons for this. Sharks do not have a “swimming bladder” (an organ that allows most fish to stabilize themselves at different depths). If sharks stop swimming they will sink. Also, most species have no mechanism for pumping water so that it will pass over their gills and bring oxygen into the bloodstream. They must depend on constant movement for this “breathing.”1. According to the writher, if we see a shark approaching, we should .2. Which of the following adjectives can best describe the shark’s rush towards the spot where some blood is .3. In paragraph 3, the writer describes the behavior of sharks in order to show .4. Which of the following statements about sharks is TRUE?5. The word “frenzy” most probably means .

In the primary school, a child is in a comparatively simple setting and most of the time forms a relationship with one familiar teacher. On entering secondary school, a new world opens up and frequently it is a much more difficult world. The pupil soon learns to be less free in the way he speaks to teachers and even to his fellow pupils. He begins to lose gradually the free and easy ways of the primary school, for he senses the need for a more cautious approach in the secondary school where there are older pupils. Secondary staff and pupils suffer from the pressures of academic work and seem to have less time to stop and talk. Teachers with specialist roles may see hundreds of children in a week, and a pupil may be able to form relationships with very few of the staff. He has to decide which adults are approachable; good schools will make clear to every young person from the first year what guidance and personal help is available—but whether the reality of life in the institution actually encourages requests for help is another matter.Adults often forget what a confusing picture school can offer to a child. He sees a great deal of movement, a great number of people—often rather frightening-looking people—and realizes that an increasing number of choices and decisions have to be made. As he progresses through the school the confusion may become less but the choices and decisions required will increase. The school will rightly expect the pupil to take the first steps to obtain the help he needs, for this is the pattern of adult life for which he has to be prepared, but all the time the opportunities for personal and group advice must be presented in a way which makes them easy to understand and within easy reach of pupils. (316 words)1. According to the passage one of the problems for pupils entering secondary schools is that .2. In secondary schools every pupil having problems should .3. It can be inferred from the passage that the author is mainly concerned about .4. Which of the following statements is TRUE?5. The most appropriate title for the passage would be .

It is doing something better than other people that makes us unique. Yet a surprising number of people still see individuality as a surface thing. They wear bright clothes, dye their hair strange colors and decorate their skin with tattoos to make some kind of social statement.The whole purpose of individuality is excellence. The people who comprehend the simple principle of being unique through performance make our entire political and economic system work. Those who invent, who improve, who know more about a subject than other people do, and who take something that doesn’t work and make it work—these people are the very soul of capitalism.Charles Kettering didn’t like the idea of cranking a car to make it start, so he invented the electric starter. Henry Ford figured out the assembly-line technique and made it possible to mass-produce automobiles. Lewis Waterman saw no need to go on dipping a pen into an inkwell, so he put the ink into the pen. George Westinghouse told the world how to stop a train, and Elisha Otis, inventor of the elevator, indirectly created the city skyline. These people understood that individualism means working at the top of one’s capacity.Fortunately, enough Americans have been inspired to do something with their uniqueness that we have developed in less than three centuries from a frontier outpost into not only a country of freedom but a country strong enough to protect that freedom. These people prized the notions of individuality and excellence above all things and thus kept the great machine functioning. The ones with the purple hair and the horrible jewelry are just along for the ride, trying to be “different” and not knowing how to go about it.The student who earns A’s on his report card has grasped the idea and has found the real meaning of individuality. So has the youngster who has designed his own spaceship, who paints pictures of the world around him, or who can name all the states and their capitals.1. According to the author unique individuals are persons who .2. People who regard individuality as a surface thing always do the following EXCEPT .3. Which is NOT true according to the passage?4. It can be inferred from the passage that __.5. In the writer’s opinion who has understood the sense of individuality?

Plant vacuoles are frequently targeted as a storage site for novel products. We have used environment-sensitive fluorescent dyes and the expression of vacuolar marker proteins to characterize the vacuoles in different organs and cell types of sugarcane. The results demonstrated that the lumen of the vacuole in the parenchyma cells of the stem is acidic (<pH 5) and contains active proteases, characteristic of lytic vacuoles. In contrast to the stem parenchyma cells, the cells of sugarcane leaves contain diverse types of vacuoles. The pH of these vacuoles and their capacity to hydrolyze protease substrates varies according to cell type and developmental stage. Sugarcane suspension-cultures contain cells with vacuoles that resemble those of stem parenchyma cells and are thus a useful model system for investigating the properties of the vacuole.

Soil quality determines the sustainability and productivity of agro-ecosystems. Several indicators, combining soil chemical, physical and biological properties, have been used to determine the effect of soil management systems on soil quality. In some soils, physical and chemical parameters have been used to measure soil quality. However, in general these parameters change slowly and several years are necessary to obtain significant differences, whereas biological and biochemical parameters could be more sensitive and rapid indicators of changes in soil management practices.

Carrot (Daucus carota), with remarkably high levels of vitamin A and other nutrients in the edible taproot, is an important horticultural crop and comprises a significant part of the horticultural market. New requirements on horticultural crops, such as enhanced resistance to pest and disease as well as enhanced tolerance to abiotic stresses, can be provided by genetic engineering techniques.

Long-term field experiments have provided important information for guiding agricultural development and are valuable for determining yield change over time, for assessing soil nutrient status and system sustainability as well as for predicting soil-carrying capacity. In China, rice (Oryza sativa L.), wheat (Triticum aestivum L.) and maize (Zea mays L.) are the main crops grown on an area of 31.7, 28.9 and 25.9 million hectares, respectively.

Directions: For this part, you are asked to write a composition on a certain topic. You should write at least 150 words and you should base your composition on the outline below:Sustainable Development1.可持续发展的实质是……2.中国在可持续发展方面做了很多努力。3.我们下一步的目标是……

Directions: In this part there is a short passage with some questions or incomplete statements. Read the passage carefully. Then answer the questions or complete the statements in no more than TEN words.For centuries man dreamed of achieving vertical flight. In 400 AD Chinese children played with a fan-like toy that spun upwards and fell back to earth as rotation ceased. Leonardo da Vinci conceived the first mechanical apparatus, called a “Helix”, which could carry a man straight up, but his was only a design and was never tested.The ancient dream was finally realized in 1940 when a Russian immigrant, an aeronautical engineer, piloted a strange looking craft of steel tubing with a rotating fan on top. It rose awkwardly and vertically into the air from a standing start, hovered a few feet above the ground, went sideways and backwards, and then settled back to earth. That vehicle was called helicopter.Imaginations were fired. Men dreamed of commuting to work in their own personal helicopter. Every man would have one in his backyard. People anticipated that vertical flight transports would carry millions of passengers as do the airliners of today. Such fantastic expectations were not fulfilled.The helicopter has now become an extremely versatile machine. It excels in military missions, carrying troops, guns and strategic instruments where other aircraft cannot go. Corporations use them as airborne offices, many metropolitan areas use them in police work, construction and logging companies employ them in various advantageous ways, engineers use them for site selection and surveying, and oil companies use them as the best way to make offshore and remote work stations accessible to crews and supplies. Any urgent mission to get to a place is a likely task for a helicopter. Among their other multitude of uses, they deliver people across town, fly to and from airports, assist in rescue work and aid in the search for missing or wanted persons.

Evolution of culture—that is, the development of forms through time has taken place. No amount of diffusion of picture writing could of itself, for instance, produce the alphabetic system of writing; as Tylor demonstrated so well, the art of writing has developed through a series of stages, which began with picture writing, progressed to hieroglyphic(象形文字的) writing, and culminated in alphabetic writing. In the realm of social organization there was a development from territorial groups composed of families to segmented societies (clans and larger groupings). Sociocultural evolution, like biologic evolution, exhibits a progressive differentiation of structure and socialization of function. A misunderstanding has arisen with regard to the relationship between evolution and diffusion. It has been argued, for example, that the theory of cultural evolution was unsound because some peoples skipped a stage in a supposedly determined sequence; some African tribes, as a consequence of diffusion, went from the Stone Age to the Iron Age without an intermediate age of copper and bronze.But the classical evolutionists did not maintain that peoples, or societies, had to pass through a fixed series of stages in the course of development, but that tools, techniques, institutions—in short, culture had to pass through the stages. The sequence of stages of writing did not mean that a society could not acquire the alphabet without working its way through hieroglyphic writing; it was obvious that many peoples did skip directly to the alphabet.1. Which of the following is probably NOT true when it comes to the art of writing?2. The phrase “culminated in” in the first paragraph means .3. What can be inferred from the first paragraph?4. Which of the following is probably NOT agreed by classical evolutionists?5. According to the theory of cultural evolution, the sequence of stages during which evolution takes place should be .

Very old people do raise moral problems for almost everyone who comes into contact with them. Their values—this can’t be repeated too often—are not necessarily our values. Physical comfort, cleanness and order are necessarily the most important things. The social services from time to time find themselves faced with a flat with decaying food covered by small worms, and an old person lying alone on bed, taking no notice of the worms. But is it interfering with personal freedom to insist that they go to live with some of their relatives so that they might be taken better care of? Some social workers, the ones who clear up the worms, think we are in danger of carrying this concept of personal freedom to the point where serious risks are being taken with the health and safety of the old.Indeed, the old can be easily hurt or harmed. The body is like a car: it needs more mechanical maintenance as it gets older. You can carry this comparison right through to the provision of spare parts. But never forget that such operations are painful experiences, however good the results. And at what point should you cease to treat the old body? Is it morally right to try to push off death by pursuing the development of drugs to excite the forgetful old mind and to activate the old body, knowing that it is designed to die? You cannot ask doctors or scientists to decide, because so long as they can see the technical opportunities, they will feel bound to give them a try on the principle that while there’s life, there’s hope.When you talk to the old people, however, you are forced to the conclusion that whether age is happy or unpleasant depends less on money or on health than it does on your ability to have fun.1. It is implied in Paragraph 1 that .2. Some social workers think that .3. In the author’s opinion, .4. The word “it” in the last paragraph refers to .5. The author thinks that __.

After the violent earthquake that shook Los Angeles in 1994, earthquake scientists had good news to report: The damage and death toll could have been much worse.More than 60 people died in this earthquake. By comparison, an earthquake of similar intensity that shook America in 1988 claimed 25, 000 victims.Injuries and deaths were relatively less in Los Angeles because the quake occurred at 4:31 a. m. on a holiday, when traffic was light on the city’s highways. In addition, changes made to the construction codes in Los Angeles during the last 20 years have strengthened the city’s buildings and highways, making them more resistant to quakes.Despite the good news, civil engineers aren’t resting on their successes. Pinned to their drawing boards are blueprints for improved quake-resistant buildings. The new designs should offer even greater security to cities where earthquakes often take place.In the past, making structures quake-resistant meant firm yet flexible materials, such as steel and wood, that bend without breaking. Later, people tried to lift a building off its foundation, and insert rubber and steel between the building and its foundation to reduce the impact of ground vibrations. The most recent designs give buildings brains as well as concrete and steel supports. Called smart buildings, the structures respond like living organisms to an earthquake’s vibrations. When the ground shakes and the building tips forward, the computer would force the building to shift in the opposite direction.The new smart structures could be very expensive to build. However, they would save many lives and would be less likely to be damaged during earthquakes.1. One reason why the loss of lives in the Los Angeles earthquake was comparatively low is that .2. The function of the computer mentioned in the passage is to .3. The smart buildings discussed in the passage .4. It can be inferred from the passage that in minimizing the damage caused by earthquakes attention should be focused on .5. The author’s main purpose in writing the passage is to __.

Plantain (大蕉) and banana are among the most important staple food crops in humid forest zone of West and Central Africa. This is due to the crops contribution to food security, employment, diversification of income sources in rural and urban areas, and contribution to the gross national product (GNP). Banana is the world’s second most important fruit crop after oil palm. It is grown in 130 countries worldwide, world production stood at 71 million metric tonnes. However no Africa country is ranked among the top 10 countries for banana production in the world while eight African countries were named among the top ten world producers of plantain with Nigeria ranking as the fifth highest producer of the crop. Presently plantains are of less importance than banana in terms of world trade in the genus but in West and Central Africa about 70 million people are estimated to derive more than one quarter of their food energy requirement from plantains. Moreover plantains have a high carbohydrate content (31g/100 g) and low fat content (0.4 g/100 g). They are good sources of vitamins and minerals, particularly iron (24 mg/kg), potassium (9.5 mg/kg), calcium (715 mg/kg), vitamin A, ascorbic acid, thiamin, riboflavin and niacin.

Abiotic stress limits crop productivity and plays a major role in determining the distribution of plant species across different types of environments. Abiotic stress and its effects on plants in both natural and agricultural settings is a topic that is receiving increasing attention because of the potential impacts of climate change on rainfall patterns and temperature extremes, salinization of agricultural lands by irrigation, and the overall need to maintain or increase agricultural productivity on marginal lands. In the field, a plant may experience several distinct abiotic stresses either concurrently or at different times through the growing season. Some common examples of the abiotic stresses a plant may encounter include a decreased availability of water, extremes of temperature including freezing, decreased availability of essential nutrients from the soil, excess light (especially when photosynthesisis restricted) or increased hardness of the soil that restricts root growth.

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