第3章 review questions

课后习题答案：Chapter 1:Review questions: 1,4,11,13,15,16,18,19,23,25,261没有不同，在本文书中，“主机”和“终端系统”可以互换使用。

终端系统包括PCs ，工作站，Web 服务器，电子邮件服务器，连接Internet 的PDA ，WebTV 等。

41 通过电话线拨号调制解调器：住宅2 通过电话线的DSL ：住宅或小型办公室3 光纤电缆：住宅4 100 Mbps 交换以太网：公司5 无线LAN ：移动电话6 蜂窝移动接入（例如WAP ）：移动电话11电路交换网络可以为一个通话保证特定数量的端到端带宽。

大多数现在分组交换网络（包括Internet ）可以提供所有端到端带宽保证。

13在时间t0发送主机开始传输。

在t1 = L/R1时，发送主机完成传输并且整个分组到达路由器（没有传播延迟）。

因为路由器在时间t1拥有整个分组，所以它在时间t1开始向接收主机传输此分组。

在时间t2 = t1 + L/R2，路由器完成传输并且接收主机接收整个分组（也没有传播延迟）。

因此端到端延迟是L/R1 + L/R2。

15a) 可以支持两个用户因为每个用户需要一半的链路带宽。

b) 因为在传输过程中每个用户需要1Mbps ，如果两个或更上用户同时传输，那么最大需要2Mbs 。

因为共享的链路的可用带宽是2Mbps ，所以在链接之前没有排队延迟。

然而，如果三个用户同时传输，那么需要的带宽将是3Mbps ，它大于共享链路的可用带宽，在这种情况下在链接前存在排队延迟。

c) 给定用户传输的概率是0.2。

d) 所有三个用户同时传输的概率是()333133--⎪⎪⎭⎫ ⎝⎛p p = (0.2)3 = 0.008。

因为当所有用户都传输时，队列增加，所以在队列增加的分数（它等于所有三个用户同时传输的概率）是0.008。

16延迟组件是处理延迟，传输延迟，传播延迟和排队延迟。

除了排队延迟是变化的，其它所有延迟都是固定的。

Unit 3 Reviewing LiteratureObjectives:- Learn how to formulate a research problem- learn how to cite other people‟s previous work- Try to be critical and related in your reviewing- Avoid plagiarismContents- Reading and discussion: sample introduction and elements in literature review.- Language focus: tense in citation and citing verbs- Writing practice: information prominent citation, author prominent citation, and weak author prominent citation- Literature reviews related to your research- No plagiarism- Classroom extension: literature review of the social effects of tourism on developing countries1.Reading Activity1.1 Pre-reading TaskA literature review is not just a summary of what you have read. It focuses on a specific topic of interest to you and includes a critical analysis of relationship among different opinions and then relates this review to the work of your own. It may be written as a stand-alone paper or to provide a theoretical framework and rationale for a research study to become a part of the introduction section, especially in term papers or journal articles. However, in a thesis or dissertation it will be an entire chapter.Read the sample introduction below and think about the following questions:What is the purpose of writing a literature view?What elements does an introduction include?How do we relate other people‟s previous work to our present research?How do we cite other people‟s previous work?1.2 Reading PassageIntroductionThe poor have traditionally t aken the brunt of the blame for causing society‟s many problems including, more recently, environmental degradation. There is a general consensus that poverty is a major cause of environmental degradation. For example, in one of the conclusions of the Bruntland Commission Report, which incidentally has been accepted as the blue print for environmental conservation, it was explicitly stated that poverty is a major cause of environmental problems and amelioration of poverty is a necessary and central condition of any effective programs addressing the environment. Following similar lines, Jalal (2010), the Asian Development Bank's chief of the environment department says, "It is generally accepted that environmental degradation, rapid population growth and stagnant production are closely linked with the fast spread of acute poverty in many countries of Asia". The World Bank joined the consensus when in the 2011 World Development Report, the Bank explicitly stated that, “poor families who have to meet short term needs mine the natural capital by excessive cutting of trees for firewood and failure to replace soil nutrients ” (World Bank 2011).However, there has been a rising trend in the economic literature which disputes the conventional theory and argues that simple generalizations of this multi-dimensional problem are erroneous and that a more complex set of variables are in play (Leach and Mearns, 2012). These studies point to demographic, cultural, and institutional factors as important variables in the poverty-environmental degradation nexus. An intricate web of factors plus the existence of feedback loops from environmental degradation to poverty makes the process of identifying causality links,if any, between environmental degradation and poverty a difficult exercise. However, these studies have been few and isolated and it is interesting to note that until recently, there has been very little in-depth coordinated empirical research in the economics of environmental degradation-poverty causality relationships.This brings to the purpose of this study. Both poverty and environmental degradation have been increasing in many developing countries; hence there is a pressing need first to evaluate and analyze the poverty-environmental degradation nexus, and second, to prescribe policy options to mitigate or eradicate these two problems.The primary objective of the paper is to analyze critically the existing literature on the poverty-environmental degradation nexus and try to make "some order out of the chaos" inherent in this complex and difficult subject. For this paper, our analysis is limited to the following four main natural resources which are under serious threat of degradation in many developing countries: i) forests; ii) land; iii) water; and iv) air. Biodiversity is excluded at this point because the preliminary literature search found only scattered and inconclusive information. However, it should not be inferred that biodiversity is less important than the four resources chosen; indeed it is an area which needs particular attention in the future.Once the natural resource sectors have been identified, a cause, impact and feedback analysis is carried out. In this manner, we hope first to identify the main agents and the degree of their contribution towards the destruction of the environment and second, the incentives or motivating factors encouraging their unsustainable activities. The impact and feedback analysis should highlight the main impacts arising from the degradation activities and the socio-economic effect these impacts have across the various income groups in the economy.1.3 Reading Comprehension1.3.1 List different opinions on poverty and environmental degradationnguage Focus2.1Tense in citationPresent tense - Authors mostly use the present tense verbs to show their opinion on another person's research, relate what other authors say or discuss the literature, theoretical concepts, methods, etc. However, the simple past and present perfect are also possible verb forms in this case. Look at these examples in the present tense: ∙Nelson (1995) remarks∙Jones (2005) stresses∙Morison (2000) advocates∙Zhang (2007) claims∙Zhambhi (2008) arguesPast tense- When you use the past tense, the reporting verb often occurs as an integral citation. In other words, citations with past tense verbs and named researchers as subject seem to have the discourse role of providing particulars for recounting events, results found or a preceding generalization or the basis for a claim, etc. In the example below, the citation reports the results of a single study.Carlson and Benton (2007) found that as they increased the participants‟stress levels, the results of their performance deteriorated.Common verbs in the past tense are: investigated, studied, compared, analyzed, found, and examined.Present perfect - The present perfect tense can be used to state that the research results are recent, expressing what has been found over an extended period in the past and up to the present to highlight the direct relevance of previous studies to the writer's own research. Look at the following example:Although the results of pervious studies showed that further research was warranted in this area, recent studies have demonstrated that educational methodology is now moving in a new direction (Jones, 2007; Karstal, 2008).2.1.1 Check the sample introduction and complete the following table.2.2Citing verbsIt is important that you learn how to cite information in a correct way. There are certain conventions to follow when citing someone‟s work. Words like “say”,“tell”, and “ask” are normally used in oral conversation s but are not appropriate in formal academic writing. The following table illustrates some appropriate words to use for reporting the work of others.Verbs for sayingJalal (1993) claimsbelievesthinksassumesindicatesnotesremarksstatesshowspoints outthat …More V erbs for sayingJalal‟s (1993) study suggestsconsidershypothesizesconcludescommentsemphasizesillustratesproposesestablishesmaintainsthat…Verbs responding to others’opinionsThe analysis of the Jalal‟s report acceptsadmitsagreesdoubtsthat …deniesarguescomments Verbs for saying a second timeJalal (1993) further/additionally assertsexplainsconfirmsmaintainsadvocatesthat …Poor patterns show that the writer has a mere grasp of the literature:Jalal (1993) says that …The Asian Development Bank (1992) states that … Leach and Mearns (1995) argue that …Better sample shows some critical thinking and sentence variety:Jalal (1993) reports that his study of …shows …The findings are supported by the Asian Development Bank (1992) replication of … Although both these studies focus on …. They have ignored … According to Leach and Mearns (1995), …2.2.2 Read three extracts on the issue of poverty and crime. Use the verbs above to cite opinions on poverty and crime.3. Writing Practice3.1 Using referencesUse citation to develop your own argument.Below are examples of parts of paragraphs using three different citation methods (The references cited have been invented for demonstration purposes only). Thesemethods can be called information prominent, where the focus of the sentence is only on the information being presented; author prominent, where the name of the author of the information is given prominence in the sentence; and weak author prominent, where the ideas of author(s) are given prominence, but authors‟names do not appear in the main part of the sentence. Observe how the different methods contribute to the way in which the writer‟s argument is developed.Information prominent citationShrinking markets are also evident in other areas. The wool industry is experiencing difficulties related to falling demand worldwide since the development of high-quality synthetic fibers (Smith, 2000).This is the default style in many areas of science. However, there are two other options, which should also be part of a writer‟s repertoire, for use when appropriate. Author prominent citationShrinking markets are also evident in other areas. Smith (2000) argued that the wool industry was experiencing difficulties related to falling demand worldwide since the development of high-quality synthetic fibers. However, Jones et al. (2004) found that industry difficulties were more related to quality of supply than to demand issues. It is clear that considerable disagreement exists about the underlying sources of these problems.Weak author prominent citationShrinking markets are also evident in other areas. As Smith (2000) pointed out, the wool industry is experiencing difficulties related to falling demand worldwide since the development of high-quality synthetic fibers.3.1.1 The following is a chart describing people living on less than 1.25 dollars.Look at the following chart and practice citing these figures by using three different types of citation.Figure: Poverty headcount ratio at $1.25 a day (% of population)Created By Swati Revankar from World Bank, 2012 Information prominent citationAuthor prominent citationWeak author prominent citation3.2 Relating literature to your researchIt is easy to write a bad literature review and difficult to write a good one. The main mistake that a lot of people make is to write a literature review that looks like this:LITERATURE REVIEWUntil recently many researchers have shown interest in the field of coastal erosion and the resulting beach profiles. They have carried out numerous laboratory experiments and field observations to illuminate the darkness of this field. Their findings and suggestions are reviewed here.JACHOWSKI (2008) developed a model investigation conducted on the interlocking precast concrete block seawall. After a result of a survey of damages caused by the severe storm at the coast of USA, a new and specially shaped concrete block was developed for use in shore protection. This block was designed to be used in a revetment type seawall that would be both durable and economical as well as reduce wave run-up and overtopping, and scour at its base or toe. It was proved that effective shore protection could be designed utilizing these units.HOM-MA and HORIKAWA (2008) studied waves forces acting on the seawall which was located inside the surf zone. On the basis of the experimental results conducted to measure waves forces against a vertical wall, the authors proposed an empirical formula of wave pressure distribution on a seawall. The computed results obtained by using the above formula were compared well with the field data of wave pressure on a vertical wall.SELEZOV and ZHELEZNYAK (2009) conducted experiments on scour of sea bottom in front of harbor seawalls, on the basis of the theoretical investigation of solitary wave interaction with a vertical wall using Boussinesque type equation. It showed that the numerical results were in reasonable agreement with laboratory experimental data.3.2.1 Consider again the purposes of writing a literature review. See if you can answer the following questions about the literature review above:1. What questions does this literature review answer?2. What questions doesn't it answer?3. Which method has the writer used to organize the literature review?4. Is it a good literature review? Why?3.3 Avoiding plagiarism3.2.1 Below are two versions of the same information, adapted from the Introduction by McNeill et al. (2007). Decide which version has the problem of plagiarism and identify where the writer has plagiarizedVersion 1:Russell and Fillery (2006), using a stem-feeding technique, have shown that in situ 15N-labelling of lupin plants growing in soil cores enabled total belowground N to be estimated under relatively undisturbed conditions, but they indicated that the technique was not adaptable to all plants, particularly pasture species.Version 2:Russell and Fillery (2006), using a stem-feeding technique, have shown that in situ 15N-labelling of lupin plants growing in soil cores enabled total belowground N to be estimated under relatively undisturbed conditions. However, this technique is not adaptable to all plants, particularly pasture species.4. Writing ProjectWrite a literature review for your research by the following steps:1. Problem formulation—which topic or field is being examined and what are its component issues?2. Literature search—finding materials relevant to the subject being explored3. Data evaluation—determining which literature makes a significant contribution to the understanding of the topic4. Analysis and interpretation—discussing the findings and conclusions of pertinent literature5. Relate the review to your research topicYou are preparing to write an essay ent itled “The social effects of tourism on developing countries”. Read the following abstract and then try to write a literature review relating to the topic according to the above mentioned steps:AbstractTourism is the fastest growing industry internationally. Popular areas of study are the economic, environmental and sociocultural impacts of tourism in developing countries. Very few studies have been conducted on the impact of tourism on the hosts‟ health status. Nowadays, the emergence of new infectious diseases or there-emergence of diseases are causing concern and travel is a major contributor to their spread. The objectives of this study were: to review literature related to the topic as a background for future research; to explore if findings from a field trip to Easter Island/Chile and Peru support the hypotheses derived from the analysis of publications; to recommend a range of research topics based on the outcome of this study; and to propose elements of a framework for the assessment of health impacts of tourism. The findings suggest that there are considerable gaps in the current knowledge on tourism‟s health impacts. Potential indirect and direct health impacts have been identified. Workplace health and safety concerns in relation to local tourism employees have been raised. A wide range of research topics has been suggested based on these findings. Finally, elements of a possible framework for understanding tourism‟s health impacts and their interrelationships have been identified.Sources from: Irmgard Bauer, THE JOURNAL OF TOURISM STUDIES Vol. 10, No. 1, MAY …99 115. Final ChecklistHere is a final checklist for writing Introduction (including literature review). Use it to check what you have written in the previous task.。

Unite 3 Doctor’s Dilemma: Treat or Let Die?Abigail Trafford1. Medical advances in wonder drugs, daring surgical procedures, radiation therapies, and intensive-care units have brought new life to thousands of people. Yet to many of them, modern medicine has become a double-edged sword.2. Doctor’s power to treat with an array of space-age techniques has outstripped the body’s capacity to heal. More medical problems can be treated, but for many patients, there is little hope of recovery. Even the fundamental distinction between life and death has been blurred.3. Many Americans are caught in medical limbo, as was the South Korean boxer Duk Koo Kim, who was kept alive by artificial means after he had been knocked unconscious in a fight and his brain ceased to function. With the permission of his family, doctors in Las Vegas disconnected the life-support machines and death quickly followed.4. In the wake of technology’s advances in medicine, a heated debate is taking place in hospitals and nursing homes across the country --- over whether survival or quality of life is the paramount goal of medicine.5. “It gets down to what medicine is all about, ” says Daniel Callahan, director of the Institute of Society, Ethics, and the Life Sciences in Hastings-on-Hudson, New York. “Is it really to save a life? Or is the larger goal the welfare of the patient?”6. Doctors, patients, relatives, and often the courts are being forced to make hard choices in medicine. Most often it is at the two extremes of life that these difficultyethical questions arise --- at the beginning for the very sick newborn and at the end for the dying patient.7. The dilemma posed by modern medical technology has created the growing new discipline or bioethics. Many of the country’s 127 medical s chools now offer courses in medical ethics, a field virtually ignored only a decade ago. Many hospitals have chaplains, philosophers, psychiatrists, and social workers on the staff to help patients make crucial decisions, and one in twenty institutions has a special ethics committee to resolve difficult cases.Death and Dying8. Of all the patients in intensive-care units who are at risk of dying, some 20 percent present difficult ethical choices --- whether to keep trying to save the life or to pull back and let the patient die. In many units, decisions regarding life-sustaining care are made about three times a week.9. Even the definition of death has been changed. Now that the heart-lung machine can take over the functions of breathing and pumping blood, death no longer always comes with the patient’s “last gasp” or when the heart stops beating. Thirty-one states and the District of Columbia have passed brain-death statutes that identify death as when the whole brain ceases to function.10. More than a do zen states recognize “living wills” in which the patients leave instructions to doctors not to prolong life by feeding them intravenously or by other methods if their illness becomes hopeless. A survey of California doctors showed that 20 to 30 percent were following instructions of such wills. Meanwhile, the hospicemovement, which its emphasis on providing comfort --- not cure --- to the dying patient, has gained momentum in many areas.11. Despite progress in society’s understanding of death and dying, t heory issues remain. Example: A woman, 87, afflicted by the nervous-system disorder of Parkinson’s disease, has a massive stroke and is found unconscious by her family. Their choices are to put her in a nursing home until she dies or to send her to a medical center for diagnosis and possible treatment. The family opts for a teaching hospital in New York city. Tests show the woman’s stroke resulted from a blood clot that is curable with surgery. After the operation, she says to her family: “Why did you bring me back to this agony?” Her health continues to worsen, and two years later she dies.12. On the other hand, doctors say prognosis is often uncertain and that patients, just because they are old and disabled, should not be denied life-saving therapy. Ethicists also fear that under the guise of medical decision not to treat certain patients, death may become too easy, pushing the country toward the acceptance of euthanasia.13. For some people, the agony of watching high-technology dying is too great. Earlier this year, Woodrow Wilson Collums, a retired dairyman from Poteet, Texas, was put on probation for the mercy killing of his older brother Jim, who lay hopeless in his bed at a nursing home, a victim of severe senility resul ting from Alzheimer’s disease. After the killing, the victim’s widow said: “I think God, Jim’s out of his misery. I hate to think it had to be done the way it was done, but I understand it. ”Crisis in Newborn Care14. At the other end of the life span, technology has so revolutionized newborn carethat it is no longer clear when human life is viable outside the womb. Newborn care has got huge progress, so it is absolutely clear that human being can survive independently outside the womb. Twenty-five years ago, infants weighting less than three and one-half pounds rarely survived. The current survival rate is 70 percent, and doctors are “salvaging” some babies that weigh only one and one-half pounds. Tremendous progress has been made in treating birth deformities such as spina bifida. Just ten years ago, only 5 percent of infants with transposition of the great arteries --- the congenital heart defect most commonly found in newborns --- survived. Today, 50 percent live.15. Yet, for many infants who owe their lives to new medical advances, survival has come at a price. A significant number emerge with permanent physical and mental handicaps.16. “The question of treatment and nontreatment of seriously ill newborns is not a single one,”says Thomas Murray of the Hastings Center. “But I feel strongly that retardation or the fact that someone is going to be less than perfect is not good grounds for allowing an infant to die.”17. For many parents, however, the experience of having a sick newborn becomes a lingering nightmare. Two years ago, an Atlanta mother gave birth to a baby suffering from Down’s Syndrome, a form of mental retardation; the child also had blocked intestines. The doctors rejected the parents’ plea not to operate, and today the child, severely retarded, still suffers intestinal problems.18. “Every time Melanie has a bowel movement, she cries,” explains her mother.“She’s not able to take care of herself, and we won’t live forever. I wanted to save her from sorrow, pain, and suffering. I don’t understand the emphasis on life at all costs, and I’m very angry at the doctors and the hospital. Who will take care of Melanie after we’re gone? Where will you doctors be then?”Changing Standards19. The choices posed by modern technology have profoundly changed the practice of medicine. Until now, most doctors have been activists, trained to use all the tools in their medical arsenals to treat disease. The current trend is toward nontreatment as doctors grapple with questions not just of who should get care but when to take therapy away.20. Always in the background is the threat of legal action. In August, two California doctors were charged with murdering a comatose patient by allegedly disconnecting the respirator and cutting off food and water. In 1981, a Massachusetts nurse was charged with murdering a cancer patient with massive doses of morphine but was subsequently acquitted.21. Between lawsuits, government regulations, and patients’ rights, many doctors feel they are under siege. Modern technology actually has limited their ability to make choices. More recently, these actions are resolved by committees.Public Policy22. In recent years, the debate on medical ethics has moved to the level of national policy. “It’s just beginning to hit us that we don’t have unlimited resources,” says Washington Hospital Center’s Dr. Lynch. “You can’t talk about ethics without talkingethics without talking about money.”23. Since 1972. Americans have enjoyed unlimited access to a taxpayer-supported, kidney dialysis program that offers life-prolonging therapy to all patients with kidney failure. To a number of police analysts, the program has grown out of control --- to a $1.4billion operation supporting 61,000 patients. The majority are over 50, and about a quarter have other illness, such as cancer or heart disease, conditions that could exclude them from dialysis in other countries.24. Some hospitals are pulling back from certain lifesaving treatment. Massachusetts General Hospital, for example, has decided not perform heart transplants on the ground that the high costs of providing such surgery help too few patients. Burn units --- through extremely effective --- also provide very expensive therapy for very few patients.25. As medical scientists push back the frontiers of therapy, the moral dilemma will continue to grow for doctors and patients alike, making the choice of to treat the basic question in modern medicine.1. 在特效药、风险性手术进程、放疗法以及特护病房方面的医学进展已为数千人带来新生。

全新版⼤学英语综合教程3课⽂原⽂及翻译unit 4Was Einstein a Space Alien?1 Albert Einstein was exhausted. For the third night in a row, his baby son Hans, crying, kept the household awake until dawn. When Albert finally dozed off ... it was time to get up and go to wor k. He couldn't skip a day. He needed the job to support his young family.1. 阿尔伯特.爱因斯坦精疲⼒竭。

他幼⼩的⼉⼦汉斯连续三个晚上哭闹不停，弄得全家⼈直到天亮都⽆法⼊睡。

阿尔伯特总算可以打个瞌睡时，已是他起床上班的时候了。

他不能⼀天不上班，他需要这份⼯作来养活组建不久的家庭。

2 Walking briskly to the Patent Office, where he was a "Technical Expert, Third Class," Albert w orried about his mother. She was getting older and frail, and she didn't approve of his marriage to Mileva. Relations were strained. Albert glanced at a passing shop window. His hair was a mess; he had forgotten to comb it again.2. 阿尔伯特是专利局三等技术专家。

在快步去专利局上班的路上，他为母亲忧⼼忡忡。

母亲年纪越来越⼤，⾝体虚弱。

怎么画四年级下册英语第三单元知识总结全文共3篇示例，供读者参考篇1How to Draw a Summary of the Knowledge of Unit 3 in the Second Semester of the Fourth Grade EnglishUnit 3 in the second semester of the fourth grade English textbook covers a variety of topics, including daily activities, hobbies, likes and dislikes, and asking and giving information about them. Drawing a summary of the knowledge learned in this unit can help students review and reinforce their understanding of the material. Here is a step-by-step guide on how to draw a summary of Unit 3:Step 1: Begin by drawing a large square on a piece of paper. Divide the square into four equal sections, representing the four main topics covered in Unit 3: daily activities, hobbies, likes and dislikes, and asking and giving information.Step 2: In the first section, draw pictures or symbols representing various daily activities, such as waking up, brushing teeth, eating breakfast, going to school, doing homework, andgoing to bed. Label each activity with its corresponding English word.Step 3: In the second section, draw pictures or symbols representing different hobbies that students may have, such as playing sports, dancing, painting, reading, and playing a musical instrument. Label each hobby with its corresponding English word.Step 4: In the third section, draw pictures or symbols representing things that students like and dislike, such as animals, foods, colors, and activities. Label each like and dislike with its corresponding English word.Step 5: In the fourth section, draw pictures or symbols representing questions that can be asked and answers that can be given about daily activities, hobbies, likes and dislikes. For example, draw a question mark and an exclamation mark for asking questions, and draw speech bubbles for giving answers. Label each question and answer with its corresponding English word.Step 6: Once you have completed drawing the summary of Unit 3, take some time to review and practice using the English words and phrases that you have included in your drawings. Thiswill help solidify your understanding of the material and improve your English language skills.In conclusion, drawing a summary of the knowledge learned in Unit 3 of the fourth grade English textbook can be a fun and effective way to review and reinforce the material. By following the steps outlined above, students can create a visual representation of the topics covered in the unit and practice using the English vocabulary in a meaningful context. Happy drawing and learning!篇2How to Draw Knowledge Summary of Grade Four Second Semester English Unit ThreeIn the fourth grade second semester English unit three, students will learn about new vocabulary related to family, such as father, mother, sister, brother, grandpa, grandma, and so on. They will also learn how to describe their family members using possessive pronouns (my, your, his, her), and learn how to ask and answer simple questions about family.To summarize the knowledge learned in this unit, here are some key points to remember:1. Family Vocabulary:- Father: A male parent- Mother: A female parent- Sister: A female sibling- Brother: A male sibling- Grandpa: A grandfather- Grandma: A grandmother2. Possessive Pronouns:- My: Belonging to me- Your: Belonging to you- His: Belonging to him- Her: Belonging to her3. Asking and Answering Questions:- How many brothers/sisters do you have?- I have two brothers/sisters.- What is your father's name?- My father's name is John.4. Drawing Activities:- Encourage students to draw their family members and label them using the new vocabulary learned in this unit.- Have students practice asking and answering questions about their family members while showing their drawings to their classmates.By practicing these key points and engaging in drawing activities, students will be able to reinforce their understanding of the new vocabulary and grammar structures learned in this unit. Drawing can be a fun and creative way for students to practice and retain the knowledge they have acquired. The more they practice, the better they will be able to communicate about their family in English.篇3Summary of Unit 3 in the 4th Grade English TextbookIn Unit 3 of the 4th grade English textbook, students learned about different topics related to daily activities, family, and responsibilities. Throughout this unit, students practiced speaking, listening, reading, and writing skills to further their understanding of the English language.The unit started with a focus on daily activities, where students learned how to talk about their daily routines usingexpressions such as “I get up at 7 o’clock” or “I brush my teeth before breakfast”. Students also practiced asking and answering questions about daily activities to improve their communication skills.Following the topic of daily activities, students explored the theme of family and relationships. They learned vocabulary related to family members such as mother, father, sister, and brother, as well as adjectives to describe them like “funny”, “kind”, or “clever”. Students engaged in activities that allowed them to talk about their own families and share experiences with their classmates.Another important aspect of Unit 3 was the concept of responsibilities. Students learned how to express obligations and duties using phrases like “I have to do my homework” or “I must clean my room”. Through this topic, students developed a sense of awareness about the importance of fulfilling their responsibilities both at home and at school.In addition to vocabulary and grammar practice, students also had the opportunity to enhance their listening and reading comprehension skills. They listened to dialogues and stories related to the unit themes, as well as read short texts to improve their reading fluency and comprehension.Overall, Unit 3 was a comprehensive learning experience that allowed students to deepen their understanding of English vocabulary, grammar, and communication skills. By the end of the unit, students were able to confidently talk about their daily activities, family members, and responsibilities in English, showcasing their progress and growth in the language.。

口腔颌面部解剖学复习思考题及病例分析Review questions and case analysis第二章颅骨一、复习思考题Review questions1．试述脑颅和面颅各骨的名称;2．何谓翼点并说明其临床意义;3．试述颅底外面的分区和各区的主要解剖结构;4．茎突有何临床意义5．从前向后依次描述颅中窝外侧部主要的裂、孔、管、沟的位置和名称及穿行其内的结构;6．试述穿过颅后窝各孔的解剖结构;7．简述颞下颌关节窝的境界和组成;8．描述颞下窝及翼腭窝的解剖境界和交通;9．简述眶下管的走行及其临床意义;10．试述上颌窦的解剖形态及其与上颌前磨牙和磨牙的位置关系;11．何谓上颌骨三大支柱简述其功能;12．试述下颌骨的薄弱部位;13,简述翼腭管的构成、交通及腭大孔的位置;14．简述颧骨的主要解剖形态;二、病例分析Case analysis1．一男性患者,37岁,因车祸送来急救;检查发现：双侧眶周围皮下淤血,形成“熊猫眼”,鼻腔内流淡粉红色液体,嗅觉障碍;从解剖学角度分析,为何出现上述症状分析：该患者为颅前窝骨折,累及筛板及眶板;颅前窝底即为眼眶顶,薄弱易破,两侧眶顶间为筛板,为鼻腔顶,其中有许多小孔为嗅神经纤维和筛前动脉通过;该患者有外伤史且受力点在额眶部,导致颅前窝骨折累及筛板,撕破该处硬脑膜及鼻腔顶粘膜,出现了脑脊液鼻漏并伤及嗅神经使嗅觉障碍,同时,外力使眶板骨折出现球结膜下出血和眼睑皮下淤血,故表现为双眼眶周青紫现象,俗称“熊猫眼”;2．患者女性,27岁,骑车被卡车撞伤,曾有昏迷-短暂清醒-再昏迷史;来院检查：右颞部皮下血肿,意识障碍,呕吐,血压升高,脉搏减慢,脉压差增大,心率呼吸减慢,双侧瞳孔不等大,同侧对光反射减弱,分析此症状及造成此症状的原因;分析：此为颞骨骨折所致硬脑膜外血肿伴有原发性脑损伤症状;颅骨该处为翼点,由额、蝶、顶,颞骨之间的缝连接,该部颅骨较菲薄,容易造成颅骨骨折,引起原发性脑损伤,此时患者出现意识障碍,随后完全清醒或意识障碍好转,但不久因该部颅骨内面硬脑膜中动脉和静脉撕破导致硬脑膜外血肿形成,再次出现昏迷,并由于血肿增大挤压大脑颞叶使其内侧面海马、钩回突向小脑幕切迹缘以下而出现意识障碍加深,瞳孔散大,一侧对光反射消失,对侧肢体偏瘫等小脑幕切迹疝症状;3．一学生,男,22岁,因球砸伤面左侧部,患者张口受限约lcm左右,左颧面部肿胀,皮下出血,压痛存在,口内咬合关系良好,X线提示颧弓“M”型骨折,如何解释该患者症状和体征分析：这是一个典型的单纯颧弓骨折的病例;颧弓和颧骨是面部比较突出的部分,常因受外力直接打击而发生骨折,其中尤以颧弓骨折多于颧骨骨折;颧弓是由颧骨颞突和颞骨颧突连接而成,此处较薄弱,骨折时多发生内陷移位,压迫颞肌以及内侧的下颌骨喙突而导致张口受限,甚至不能张口,局部疼痛,伤侧面部早期扁平,数小时后随着软组织肿胀而不易觉察,只有靠手指触诊方可诊断;常见的骨折类型有：三线骨折“M”型和双线骨折;4．患者女性,35岁,肥胖体型;因右上颌侧切牙和尖牙根端囊肿手术作眶下神经阻滞麻醉口外法注射;术者在鼻翼外侧lcm处刺入皮肤直达骨面后向上后方向深入,始终未及眶下孔,经反复调整位置后,突然感阻力消失,然病人感眼球刺痛,随即拔出针头;请问术者操作是否正确,如何解释患者反应分析：眶下孔位于眶下缘中点下方～1.0cm处,用手指扪及眶下缘最低点有一凹陷,用力压迫该处,可有明显痛觉此即眶下神经出眶下孔处;眶下孔进入眶下管,朝向上、外、后走行,眶下管长约1.5cm,故临床进针应朝向上、外、后,同时应注意针尖角度,角度过小时针尖指向偏上,容易越过眶下缘而刺伤眼球,此种情况尤其在肥胖型病人中多见;5．一女性患者,18岁,因下颌高度不足、面部不对称而求治;询问病史,幼儿时期曾有右侧中耳炎反复发作史近5年;检查：上下颌比例失调,面下1／3过短,呈“鸟嘴样”畸形,口内咬合关系异常,牙列拥挤,X线测量右下颌过短,试从解剖学角度分析此临床体征;分析：在解剖结构上,中耳与颞下颌关节紧密相邻,儿童岩鼓裂处,只有很薄软组织隔开,当患化脓性中耳炎时脓液可直接扩散到关节；而髁状突是下颌骨生长的一个重要中心,在头颅骨中是最后停止生长活动的;从胚胎12周开始生长到18～20岁左右软骨才钙化,髁状突的生长使下颌向前向下生长,面部的深度及高度得以增长;该患者由于在生长期髁状突因炎症而破坏了生发中心,导致右下颌停止生长出现面部发育障碍,咬合关系紊乱; 6．患者男性,45岁,左上颌第一磨牙残冠根尖周反复发炎,要求拔除;术者在仔细检查、摄片后,局部麻醉下行分根挺拔,不料,在颊侧远中根上挺取根时突感落空感,随即牙槽窝内空虚,擤鼻时漏气;试从解剖学角度分析可能的原因及今后应注意的事项;分析：上颌前磨牙及上颌磨牙的牙根与上颌窦底邻近,有时根尖与上颌窦粘膜紧密相连,其间无骨板间隔,其中尤以上颌第一磨牙根尖距上颌窦底壁最近,在慢性根尖感染时,根周骨质破坏致根尖部牙周膜与上颌窦底粘膜可发生粘连,因此,去除断根时,容易进入上颌窦,造成上颌窦瘘,这一解剖特点,应引起高度重视;第三章颞下颌关节一、复习思考题Review questions1．从解剖学观点叙述造成开口困难可能的原因;2．颞下颌关节主要的解剖生理学特点是什么3．从解剖生理学方面分析为何全身关节中颞下颌关节发生脱位和半脱位的发病率最高4．试分析为什么人类颞下颌关节出现明显的滑动运动;5．试分析颞下颌关节运动受哪些因素制约;二、病例分析Case analysis1．一青年男性患者,因完全不能开口已7～8年来就诊;询问病史：既往无全身疾病,颌面部无外伤史,无全身关节病史;唯在一岁左右感冒咳嗽高热后右侧耳痛,流脓液,现耳部已恢复正常;检查患者全身一般状况良好;牙颌面部呈小下颌畸形,颏部明显后缩,并向右侧偏;面部右侧稍丰满,左侧呈扁平状,完全不能开口;X线片见右侧关节腔消失,髁突和关节窝融合为致密团块呈骨球状;两侧下颌角前切迹明显凹陷,左侧关节X线影像基本正常;诊断为右侧颞下颌关节强直;试问,从病史所述的一岁左右右耳痛流脓与颞下颌关节强直发病有无关系如果有,从解剖上如何解释从解剖上怎样解释小下颌畸形及两侧面部不对称;分析：引起颞下颌关节强直常见病因有二：①外伤,②化脓性感染;此患者在婴幼儿期间有化脓性中耳炎病史,此时岩鼓裂、鼓鳞裂尚未完全骨化封闭,当中耳有化脓性感染时,脓液可扩散到关节窝引起化脓性关节炎;髁突是下颌骨生长发育中心之一,因化脓性感染破坏了髁突生长中心,因此不能正常生长发育使右侧下颌支、体部都比左侧短小而导致两侧面部发育不对称;2．一中年女性患者,因左侧颞下颌关节响5～6年来就诊;询问病史：既往无全身疾病;颌面部无外伤史,也无全身关节病史;唯睡眠不好,白天常打哈欠,喜欢吃硬食物,如咬小核桃、榛子之类的坚果;左侧颞下颌关节区不痛;检查患者全身一般情况良好;牙颌面发育基本正常;开口5.0cm,开口型偏斜呈“-↓”;开口时下颌先向左侧偏,并可闻明显弹响声,然后下颌复原至正中继续开口;弹响发生在开口初;局部关节区压痛-;右侧关节未异常所见;牙合关系基本正常;X线片见关节骨质基本正常;唯左侧关节间隙有改变;试问,开口运动是否过大,开口型为什么偏斜,从解剖上怎样解释开口型异常;分析：一般自然开口度在～4.0cm,而此患者开口度达5.0cm;开口度过大,可能关节结构较松弛;引起关节结构松弛的因素从病史上提供的线索为经常打哈欠,经常使下颌到最大开口度而把韧带拉松,经常吃硬坚果类食物,也易损伤关节韧带;因为关节结构松弛,使盘—髁突复合体松弛关节盘前移;开口运动时,关节盘和髁突运动不协调,开口初时髁突的横嵴挤压关节盘后带后缘,而产生开口初弹响,因此开口初时下颌偏向左侧,弹响声过后,盘一髁突复合体关系又复正常,故开口型又复正常,因此出现“-↓”开口型;3．一中年男性,因开口受限3～4年来就诊;询问病史：既往无全身疾病,颌面部无外伤史,无全身关节病史,有夜磨牙史;3年前有左侧颞下颌关节弹响疼痛史,后弹响消失,逐渐开口受限;检查患者全身一般情况良好,牙颌面部基本正常,开口2cm,开口型“＼↓”,右侧髁突有滑动运动,左侧髁突有动度但无滑动运动;两侧关节区压痛-,弹响-,抬关系基本正常;X线片见左侧颞下颌关节腔变窄,髁突皮骨质边缘消失,表面不整齐,有较多的骨质破坏;关节镜见左侧关节上腔有瘢痕条索粘连;右侧关节-;试问从解剖因素如何解释开口受限,开口型“＼↓”偏向左侧,左侧髁突无滑动;分析：依病史可知此患者曾有颞下颌关节紊乱病,关节盘移位等病史,现关节镜证实,左侧髁突和关节窝之间有瘢痕条索,因此影响左侧髁突运动;由于是条索,未广泛粘连所以髁突有转动;但不能作滑动运动;而右侧髁突正常可以作滑动运动;所以开口时右侧滑动左侧转动,开口型呈“＼↓”,下颌偏向左侧;由于左侧髁突无滑动运动,不能作大开口运动,虽然右侧关节正常,但是因颞下颌关节是左右联动关节,一侧开口受限,就影响整个下颌正常开口运动;第四章肌一、复习思考题Review questions1．表情肌的特点是什么2．简述表情肌的分群及作用;3．简述运动下颌骨的肌肉名称、起止点、功能及神经支配;4．简述腭咽部肌的组成及作用;二、病例分析Case analysis1．一位20岁的男性患者,左侧磨牙后区胀痛不适3天,咀嚼吞咽时加重,偶向左侧耳颞部放射,且出现张口受限现象;查体：可见左侧磨牙后区软组织及牙龈红肿,左下颌第三磨牙近中阻生,轻压冠周软组织,可见脓性分泌物;实验室检查：血液中白细胞总数及中性粒细胞比例均明显增高;X线检查：可见左下颌第三磨牙近中低位阻生,骨组织未见异常;请分析患者张口受限的原因;分析：根据患者的病史、体征及辅助检查结果,不难做出诊断,即“左下颌智齿冠周炎”;在冠周炎时,炎症可向周围软组织及间隙扩散,如磨牙后区、咬肌间隙、翼下颌间隙等,当炎症波及咀嚼肌而引起肌痉挛,尤其是升颌肌群痉挛咬肌、颞肌、翼内肌时,升降颌肌群的动态平衡受到破坏,因而导致张口受限;同样道理,当恶性肿瘤侵犯咀嚼肌引起升颌肌群痉挛时,亦会导致张口受限;2．一位30岁的女性患者,被石块击中颏部半小时,面部无开放性伤口,咬合关系错乱,自觉呼吸困难;查体：可见双侧颏孔区之间骨段有明显动度,X光片显示双侧下颌骨颏孔区完全性骨折;请分析患者呼吸困难的原因;分析：患者为双侧颏孔区骨折,两侧后骨折段因升颌肌群的牵拉而向上前方移位,前骨折段则因降颌肌群的牵拉而向后下方移位,致颏部后缩颏舌肌附着点后移导致舌后坠,阻塞呼吸道上口,故而引起呼吸困难;3;一位6岁男性患儿,出生后即发现腭部裂开,自腭垂至切牙孔完全裂开;患儿说话鼻音重,口齿不清,听力下降;试分析该患儿发生上述症状的解剖学原因;分析：当正常人发音时,软腭肌肉收缩,其中后1／3部向咽后壁、咽侧壁靠拢,并与咽上缩肌活动配合,使口腔与鼻腔的通道部分或全部隔断,称为腭咽闭合;该患儿为一腭裂患者,硬、软腭裂开,口鼻相通,破坏了软腭五对肌肉的肌纤维在软腭中线交织成拱形的结构,即无法形成有效的腭咽闭合,导致鼻音重,口齿不清,同时因腭帆张肌和腭帆提肌附着异常,使咽鼓管活动障碍,影响中耳气流平衡,易于发生中耳炎;另外腭咽闭合功能障碍,易引起食物反流,也可形成中耳炎,导致听力障碍;4．一16个月的男婴因脖子偏斜由其母亲带来就诊;检查见患儿的头偏向右侧,面朝向左侧;追问病史得知患儿于出生时因难产而使用产钳助产;根据你所掌握的解剖学知识,试分析该患儿的哪一肌肉受到了损伤;分析：胸锁乳突肌为唯一使头屈向同侧、面转向对侧的肌肉;在患儿出生时因难产而使用产钳助产,在此过程中损伤了右侧胸锁乳突肌,造成局部血肿;随着血肿的机化,使右侧胸锁乳突肌收缩变短并牵拉头部,从而导致患儿斜颈的上述症状;第五章涎腺一、复习思考题Review questions1．试述三对大唾液腺的形态、位置、毗邻、导管的走行及开口位置;2．腮腺鞘有何特点其临床意义是什么3．说明舌下腺导管的组成;4．画简图说明舌下腺、下颌下腺深部和浅部、下颌舌骨肌、下颌下腺导管、舌下腺导管、舌神经的位置关系;二、病例分析Case analysis1．一位30岁的男性患者,因右侧下颌下区进食时反复肿胀半年余而就诊;检查：可见右侧下颌下腺肿大变硬,挤压腺体其导管口有脓性物流出：右侧口底下颌下腺导管中份可触及绿豆大小硬结；下颌横断抬片示右侧下颌下腺导管内有一约5mm × 3mm之椭圆形高密度影;临床诊断为：右侧下颌下腺涎石并发炎症;请从解剖学角度,分析该患者所出现上述症状的原因并说明为何下颌下腺易发生涎石病;分析：患者进食刺激腺体分泌唾液,当导管结石形成后,使唾液正常排出受阻,腺体内压增大,产生腺体肿胀不适,久之导致腺体慢性炎症及纤维化,故临床检查时出现腺体增大变硬,挤压腺体有脓性物自导管排出;下颌下腺易发生涎石病的原因主要有两个方面：从解剖学角度来讲,下颌下腺导管长且自后下向前上走行,全程较曲折,唾液易淤滞,排出缓慢易形成涎石；同时,其导管开口粗大,异物容易进入导管而诱发结石；从生理角度来讲,下颌下腺为混合性腺体,唾液中钙含量远较腮腺分泌液高,也是结石形成的原因之一;2．一位45岁的男性患者,左侧口底硬性肿块一年、左侧舌麻木不适2个月而就诊;查体：可及左侧口底3cm×2cm大小肿物,质地坚硬,表面结节状,活动度差,有触痛,经活组织病理检查确诊为左舌下腺腺样囊性癌;请分析患者产生左侧舌麻木的原因;分析：腺样囊性癌易沿神经扩散,此患者病变发生于左侧舌下腺,从解剖学方面分析,舌下腺的内侧为颏舌肌,二者之间有舌神经及下颌下腺导管穿行,故舌下腺的恶性肿瘤易侵犯舌神经而出现患侧舌体麻木的临床症状;3．一女性患者,65岁,右侧完全性面瘫半个月,临床检查见右咽侧壁隆起,触之质硬,不活动,CT检查示右侧腮腺深叶占位性病变,界限不清,并向咽侧壁突出,临床诊断为右腮腺深叶恶性肿瘤;请分析患者右咽侧壁隆起及右侧面瘫的原因;分析：腮腺深叶的尖端紧邻咽旁间隙,肿瘤发生于腮腺深叶,由于被覆于腮腺浅面的筋膜致密而腮腺内侧面的筋膜较薄弱,故藏于下颌后窝腮腺深叶的肿瘤可经此薄弱区突向咽旁间隙,在口内可见咽侧壁出现肿块；又由于面神经穿行于腮腺深、浅两叶之间,与腮腺关系密切,当发生于腮腺的恶性肿瘤侵犯面神经时,可导致其所支配的表情肌瘫痪,在临床检查时出现患侧面瘫的体征;4．一男性糖尿病患者,76岁,腹部外科手术后4天,突发左侧耳垂下方红肿,疼痛剧烈,并向耳颞部放射,体温38.2℃,临床检查左腮腺区有可凹性水肿,无波动感;请从解剖学角度解释其临床现象并说明腮腺脓肿切开引流时的注意事项;分析：该患者的病史及症状符合左侧急性化脓性腮腺炎;腮腺表面覆盖着颈深筋膜浅层形成的腮腺筋膜,即腮腺鞘;由于腮腺鞘的浅层特别致密,故在临床检查时腮腺脓肿无波动感,可在腮腺区皮肤出现可凹性水肿;此外,由于腺体内压增大,产生刺激,导致疼痛剧烈,脓肿压迫耳颞神经,疼痛可向耳颞神经的分布区颞下颌关节区、外耳道、耳颞部放射;腮腺鞘同腺体结合紧密并深入腺体内部,将其分成多个小叶,化脓时形成许多独立的小脓腔,切开引流时应注意分开各个腺叶的脓腔,以利于引流彻底、通畅;第六章血管一、复习思考题Review questions1．描述颈外动脉的行程及主要分支;2．描述颞浅动脉的行程、主要分支及分布;3．简述上颌动脉的行径及分段;4．简述面动脉的行径及主要分支;5．描述舌动脉的行径及分布;6．描述上颌动脉翼肌段的行径及分布;7．描述上颌动脉下颌段的行径及主要分支分布;8．简述上颌动脉翼腭段的行径及主要分支;9．简述上牙槽后动脉的行径及分支分布;10．描述下牙槽动脉的行径及分布;11．描述上牙槽前、中动脉的行径及分布;12．说明腭降动脉的行径及分布;13．简述面静脉的行程及收纳静脉血的范围;14．简述面静脉的交通情况及临床意义;15．描述下颌后静脉的行程及收纳静脉血的范围;16．描述翼丛的位置及交通;17．简述颈外静脉的走行及收纳静脉血的范围;18．颅内外静脉是如何沟通的19．简述颈内静脉的行程及收纳范围;二、病例分析Case analysis1．某女青年,鼻旁生一绿豆大小的疖肿,因嫌其影响美观,自行对疖肿进行挤压;5日后出现头痛、双眼周围肿胀,眼球外突,呼吸急促而入院,经抗炎和对症处理,无效而死亡,试分析其死亡原因;分析：此处静脉血回流通过面静脉,该处特别是鼻根部与口角连线的区内,称面部危险三角区脓血栓由于唇部肌肉的活动有可能进入面静脉,该静脉有时缺少静脉瓣特别是口角连线的上方静脉瓣的出现率少;如处理不当局部挤压、搔刮等,脓栓可经眼下静脉、面深静脉和翼丛逆行向颅内播散,引起海绵窦化脓性血栓性静脉炎而出现上述症状,严重的可导致死亡;2．某男,因车祸致颜面、颈、咽部出血,在受伤现场,局部压迫创口无法止血,请根据所学解剖知识,提出暂时止血的措施;分析：压迫伤口止血无效,可指压损伤动脉的近心端,达到暂时止血的目的;为了确保该方法可靠、有效,需满足以下条件：易扪及该动脉搏动；被压迫部位的基底有骨支撑;口腔颜面部可通过压迫以下三条知名动脉达到暂时止血的目的：指压耳屏前方,可止住由颞浅动脉供应区域创口的出血；指压咬肌前下角处,可止住面动脉供应区的创口出血；在紧急状况下用拇指压迫患侧的胸锁乳突肌前缘的颈总动脉,可暂时止住口咽部的严重出血由于此法可引起心搏骤停等严重并发症,一般不用;3．某男,因锅炉爆炸,致使一约4cm长的管状金属物从右侧颈部穿入,滞留于软组织内,并部分进入气管;术中取出异物时,突然出现泉涌状大出血,即行右侧颈外动脉结扎术,无效;经查,颈内静脉不充盈,遂在颈上部、胸锁乳突肌深面对出血部位进行缝合结扎将血止住,送回病房观察;但患者一直没有苏醒,后出现双侧瞳孔不等大,对光反射消失,并于术后34小时死亡,死亡后拍CT发现：右侧大脑组织严重水肿,并严重向左侧偏移;试分析术中出血原因和术后患者死亡原因;分析：根据术中出血的部位和严重程度,应考虑是颈部知名大血管被损伤;根据结扎颈外动脉不能控制出血,应考虑是颈内静脉损伤;该患者死因是：在结扎颈内静脉同时误扎了颈内动脉;结扎一侧颈内静脉后,由于静脉血回流受阻,使颅内压升高;加之误扎了颈内动脉,导致一侧大脑出现严重缺血4／5的大脑血供靠颈内动脉,更加重了脑水肿,导致颅内压升高,而出现脑疝致死;第七章面颈部淋巴结核淋巴管一、复习思考题Review questions1．掌握腮腺淋巴结、下颌下淋巴结、面淋巴结及颏下淋巴结的位置、收集范围及淋巴流向;2．了解枕淋巴结和耳后淋巴结的位置、收集范围及淋巴流向;3．掌握颈浅淋巴结、颈深淋巴结群的位置、收集范围、淋巴流向及临床意义;4．了解咽后群淋巴结和颈前群淋巴结的位置、收集范围及淋巴流向;5．了解右淋巴导管的组成及注入部位;6．了解胸导管的行程及注入部位;二、病例分析Case analysis1．左舌癌患者在接受左颈淋巴清扫术后第三天,出现左锁骨上窝肿胀,并逐渐加重,穿刺出乳白色液体;试分析什么结构的损伤导致了该症状的出现,并从解剖学角度说明其结构特点;分析：患者在接受左颈淋巴清扫术时左颈根部的胸导管受到了损伤,术后出现了乳糜漏;如果与外界穿通,则形成乳糜瘘;颈根部的胸导管易受损伤的解剖学原因如下：①胸导管管壁薄,管径较细,多为～0.5cm；②胸导管穿行于脂肪结缔组织之间,其色泽与周围所包绕的结缔组织相近似,不易分辨清楚；③胸导管从胸部后纵隔上升到注入静脉角时,在颈根部的行程呈一弓形,高出锁骨上约～5cm,个体差异很大,有的胸导管位置很低,在手术时不能见到,而有的高出锁骨5cm,极易受损,④胸导管可呈一干、两干、三干或四干型图7-7,在颈根部终止的部位也不恒定,可终止于左静脉角、左颈内静脉或左锁骨下静脉等,因而其走行途径有变异,或呈不典型的弓形,或呈斜行,⑤胸导管颈段与颈内静脉关系密切,2／3的胸导管从颈内静脉外侧深面经过,而约有1／3的胸导管颈段从颈内静脉的前方经过,该位置正好处于颈淋巴清扫术时需要显露的层次;2．某患者左额部皮肤鳞癌手术切除后二年,发现左腮腺有肿大包块,并累及左腮腺区皮肤,病理检查报告为鳞癌;试从腮腺区转移性包块与原发灶之间的关系,说明腮腺淋巴结收集淋巴的范围及治疗时应注意的解剖特点;分析：依据腮腺淋巴结的收集范围,可以推断该患者左额部皮肤鳞癌术后发生了左腮腺淋巴结转移;根据面颞部淋巴回流特点和对肿瘤转移的观察,Storm1977提出易发生腮腺淋巴结转移的解剖区域：从耳廓沿冠状缝向上到颅顶矢状缝,向前经眉尖点、鼻根部沿面动、静脉至下颌下缘的咬肌前缘,经下颌下缘向后到下颌角,再向上后经胸锁乳突肌前缘至耳廓根部,此区域为腮腺淋巴结转移的高度危险区,称为Storm区图7-8;Storm区包括同侧额部、前中份颞部、眼睑、后颊部、腮腺咬肌区及耳廓区域,此区的淋巴可注人腮腺淋巴结或颈深上淋巴结,提示在治疗该区的恶性肿瘤时,应特别注意有。

1.11.Different from personal writings, academic writings must be professional, objective, formal and logical. (对)1.21.What are the main features of academic writing? 全选Objectivity formality explicitness responsibility hedging2.You’d better make strong claims in your academic writing. (错)1.31. IMRad structure is good for all the journal articles in all the disciplines. (错)2. IMRaD structure includes the following parts:(全选)Methods Results discussion introduction第一章章节测试General introduction1.The structure of the journal article in all disciplines is the same.(错)2.If you are writing a paper in order to answer a specific question subjectively, the IMRaD structure willmost likely serve your purposes best.（错）3.The goal of using the IMRaD format is to present facts objectively, demonstrating a genuine interestand care /in developing new understanding about a topic. (对)4.Many disciplines tend to combine the results and discussion section, instead of dividing findings frominterpretations of these findings. (对)5.The tone of academic writing can be very different depending on the discipline you are writing for.(对)6.Discussion illustrates ().what the findings mean.7.To be objective, which is the best choice in academic writing? ()It is a very challenging study.8.The main purpose of the method section is to tell () you did it . how9.Which are the features of academic ? (全选)formality explicitness responsibility objectivity10. The Introduction tells () and () you did the research, What why2.1.11. The title is the most-read and first-read part of an academic paper. (对)2. A good title for a research paper should accomplish the following goals :(全选)A good title predicts the content of the research paper. A good title should be interesting to the reader. A good title should reflect the tone of the writing. A good title contains keywords that will make it easy to access by a computer search.2.1.2A long title with too many descriptive words or terms with multiple meanings may lead to misunderstandings. (对)2.2.1The title is the first-read part of the paper , so it is better to create the title first and then write the article. (错)“COVID-19 face masks: A potential source of microplastic fibers in the environment” is not a good titl e, because we can never use abbreviations or acronyms in the research paper titles. (错)One of the rules of title writing is to use the right capitalization, which is the best choice for you when submitting your paper? ()The guidelines to the authors of your target journal are the best directions for you to make the decision. So follow them strictly.2.2.2We usually have () steps to create a good title.5The questions we usually ask ourselves when start to create a final title are (), (), () and ().全选What is my research paper about? What methods/techniques were used? What or who was the subject of my study? What were the results?第二章章节测试Title1.A wrong title choice can break the quality of the paper you submit.. (对)2.The general title is much better than the detailed one. (错)3.“AE and Related NDE techniques in the fracture mechanics of concrete” is not a good title, because we can never use abbreviations or acronyms in the research paper titles. (错)4.It is not good to contain keywords in the title, because they are usually too difficult to understand. (错)5.We usually use the parallel structure to make the title unified. (错)6.()is the most frequent structures occurred in the research paper titles in sciences. The nominal group construction7.To make the title easier to access by a computer search, we usually contain () in the title. important key words8.We’d better create the final title () the paper writing. After9.The main functions of the title are: ()Attracting the readers Presenting the core contents Indexing10.The requirements to make a good title are: (全选)Being descriptive Being brief and interesting Being standard Being unified.3.1.11.The abstract covers the following sections: Introduction, Method, Result, Discussion and conclusion,just the same of IMRaD structure. (对)2.An abstract is “a concise summary of the whole paper”,An abstract is “a concise summary of the wholepaper”, providing readers with a quick overview of the paper and its organization. (对)3.1.21.The main types of the abstracts are:(全选)Descriptive abstracts Informative abstracts Structuredabstracts All of the above2.The main features of the abstract are: (), (), and ().conciseness objectivity completeness3.1.31. An descriptive abstract is the condensed version of the whole paper, it usually has four key elements in the body of an abstract. They are: Introduction, Methods, Results, Discussion and Conclusion.错2.The () part should be the longest part of the informative abstract. Results3.2.11.Write the abstract after the draft is done. (对)2.Active voice should be avoided in an abstract writing, because it is too subjective. (错)3.The abstract is text-only writing. So never include Images, illustration figures and tables.对3.2.21.Reveal your findings by listing all the results from your Results section. This part will include thedescription of the results ofReveal your findings by listing all the results from your Results section.This part will include the description of the results of your research, whether you supported or rejecteda hypothesis.(错)2.The questions that you usually try to answer in the abstract are: (全选).What did you do and why?How did do? What did you find? What do the findings mean?第三章章节测试Abstract1.The abstract section can work as the decided part of a research paper to be published or not. (对)2.The abstract works as a marketing tool. It is selling your paper to the editors and readers, helpingthem to decide “whether there is something in the body of the paper worth reading”. (对)3.The abstract is text-only writing. So never include Images, illustration figures and tables. (对)4.The descriptive abstract includes information about the purpose, scope and methods , the majorfindings , results and conclusions of your research.(错)5.The informative abstract includes the results and discussions of the research, but the descriptive onedoes not. (对)6.The sequence of questions that you usually try to answer in the abstract are: (A )1）What did you do and why?2）How did do?3）What did you find?4）What do the findings mean? A. 1）-2) - 3) -4）7. Which kind of the abstract is it? () “Various studies in inspection have demonstrated the usefulness of feedforward and feedback in improving performance. However, these studies have looked at the search and decision making components separately. Hence, it is difficult to draw generalized conclusions on the effects of feedforward and feedback for inspection tasks that have both search and decision making components. In response to this need, this study evaluates the individual and collective effect of feedforward and feedback on an inspection task that has both the search and decision-making components. For this purpose, the study used a computer simulated inspection task generated by the VisIns program. Twenty-four subjects, randomly assigned to various conditions, performed an inspection task wherein the feedforward and the feedback conditions were manipulated between subjects. Defect probability and the number of defects were also manipulated within subjects. Subsequently, the search and decision-making performances were analyzed and interpreted .”descriptive8.Which kind of the abstract is it? (). As humans accelerate the pace of marine development, autonomous underwater vehicles () are increasingly attracting worldwide attention. Due to the limitations of carrying energy and battery technology, AUV's endurance is nonideal. Therefore, designers usually make AUVs more streamlined to reduce drag. Here we show that when a layer of porous material is attached to an AUV's surface, the AUV's drag changes significantly. In this paper, simulations of the basic body of a REMUS100 and SUBOFF submarine model were carried out under multiple conditions. It is found that the drag increases as the porous viscosity coefficient or the thickness of the porous material increases. When REMUS100 and SUBOFF models are attached to the porous material with suitable porous viscosity coefficient, their drag becomes smaller. Boundary layer theory is also used to explain and analyze the phenomenon of the proportional increase of viscous pressure drag when using porous material, which is verified by vertical plate numerical simulations. Finally, we tested the mechanical properties of porous nickel and aluminum alloy 6061, and found that the porous material does have an effect of drag reduction, and can reduce the fluctuation range of the drag during the movement. Informative9.The () part should be the second-longest part of the informative abstract ? Methods10.The abstract should express your central idea and your key points, including the () or () of the researchyou discuss in the paper. Implications Applications4.1.11.Based on introduction, the readers can know the clues of your critical thinking. (对)2.Introduction cannot show the purpose clearly. (错)4.1.21. Introduction includes () parts in an academic paper. 52. In background, we need to introduce the general situation of the research field. (对)4.2.11. Even a broad opening needs to be clearly related to your topic. (对)2. We usually use three tenses in the section of Introduction. They are (), (), and (). simple present simple past present perfect4.2.21. In literature review, we’d better develop it from the more general context to the more specific topic. (对)2. The words like () and () are used to express people’s interest and significance of the study.Attention importance4.2.31. The sentence like “… has been studied extensively in recent years” is usually used to show () in Introduction. Background2. The sentence like “The present study will mainly explore…” is usually used to describe () in Introduction. purpose第四章章节测试Introuduction1. Introduction leads the audience from a general topic area to a certain topic of inquiry.对2. Introduction tells the readers why they make the investigation, where they start, and where they intend to go to. (对)3. Even a broad opening needs to be clearly related to the topic. (对)4. In the section of literature review, we’d better develop it from the more specific topic to the more general context. (错)5. We can use logical connectives to relate the information into a whole part. (对)6. The section of purpose clearly indicates the specific () that guides the research. Objective7. Literature review is about the () studies. Previous8. In the part of research gap, we display the points that (). are not studied yet9. Which are the functions of Introduction? () creating a first impression highlighting the topiclimiting the research scope10. The research background is usually presented with ( ) and ( ). reviewed literature recent development5.1.11. There are () common types of literature reviews. 22. A literature review usually has () functions. 65.1.21.The four organizational methods in literature review are (), (), () and ().全选by chronological orderby theoretical perspective by the themes to be addressed by methodology5.2.11. Criticizing other’s work without any basis can be beneficial to your paper. (错)2. There are () steps to develop a literature review. 45.2.21. “Summarizing” is a good way to avoid plagiarism. (对)2. To avoid using convoluted sentences can help us to achieve coherence.(对)5.2.31. The sentence like “… have been developed to do…” can be used to emphasize th at certain topic is used for certain purpose. (对)2. We usually use three tenses in writing a literature review. They are: (), (), and (). simple present simple past present perfect第五章章节测试Literature review1. Literature reviews are aimed to summarize some sources and provideLiterature reviews are aimed to summarize some sources and provide necessary information about a topic. (对)2. To organize the literature review by chronological order is to trace the development of the topic over time from the latest work to the earliest. (错)3. A well-written literature review is about a simple summary of prior works. (错)4. We must point out the shortcomings of previous works. (错)5. We need to avoid too much direct quoting. (对)6. When we summarize the main idea, () is a good and common method. Paraphrasing7. To make our review cohesive, we can repeat (), or use some addition connectors. key words8. There are () central techniques to show attitude or stance. 59. In the section of literature review, we collect information and sources of relevant topics from (), (), (), and so on.scholarly articles academic conference speeches dissertations/theses10. The two types of citations are () and (). information prominent citation author prominent citation6.1.11. The investigation method is used to collect materials about the current situation or historical situation of the research topic. (对)2. Academic norms are some basic procedures, methods and requirements that researchers should follow in the process of scientific research. (对)6.1.21. We need to describe the procedure employed in chronological order. (对)2. The three moves for writing Materials and methods are (), (), and (). contextualizing study methodsdescribing the study analyzing data.6.2.11. If you use anyone else's work to help you apply your methodology, discuss those works and show how they contribute to your own work. (对)2. We don’t need to discuss the weaknesses or criticisms of the methods you've chosen. (错)6.2.21. The description of the research procedure and the various materials used in each step is usually used with the simple past tense. (对)2. According to Ben Mudrak, there are () rules to write a good Materials and methods section. 4第六章章节测试Materials and methods1. The section of Materials and methods is a description of what was actually done. (对)2. The investigation method is used to just collect materials about the current situation. (错)3. Research methods in arts and science are different. (对)4. You must include enough detail that your study can be replicated by others in your field. (对)5. Reading other research papers is a good way to identify potential problems that commonly arise with various methods. (对)6. In terms of Data Analysis, it tells the reader how the () were analyzed. Data7. The description of the research procedure and the various materials used in each step is usually used with (). the simple past tense8. If the research material is conventional and not a specific material reported in the paper, we use (). the simple present tense9. The qualitative method refers to use (), (), and () to process the obtained materials. induction and deduction analysis and synthesis abstraction and generalization10. The three moves for writing Materials and Methods include (), (), and ().contextualizing study methods describing the study analyzing data7.1.11. 1. Results section in a journal paper is about“what was found” in the experiment.对2. Common non-textual elements may include ().graph histogram matrix7.1.21. Non-textual elements may be used as many as you like. (错)2. Non-textual elements should follow the following guideline: () cite the source7.2.11. Non-textual elements may be used as many as you like. (错)2. Non-textual elements should follow the following guideline: () cite the source7.2.21. In results section, abbreviations are not preferred to be used frequently. (对)第七章章节测试Results1. Figures and tables are the main aids in illustrating the results section . (对)2. A chart or a table may help you highlight the important pieces of information in your paper. (对)3. Data listed in the results section should be carefully selected and revised in the journal paper. (错)4. In results section, background information should be reported again in order to facilitate the comparison or contrast of those specific results. (错)5. How to design your graphs in your journal paper?() Make each line on a graph as easily distinguishable as possible6. Non-textual elements are used for _____. () a certain purpose7. It is necessary to ______ your results in detail in the results section. () list8. Embedding a chart, a table or other non-textual elements into the paper can bring added _____to the research. () clarity9. Results section includes the following elements: () an introductory context a summary of the key findings an inclusion of non-textual elements10. For most research paper formats, there are the following ways to present and organize the results. ()Presenting the results followed by a short explanation of the findings. Presenting a section and discussing it.8.11. We learned that the result section answers the question“W-H-A-T”, and then the discussion section answers the most important question, namely, ____. SO WHAT2. In some papers, results section and discussion section are combined into one. (对)8.2.11. You may repeat the information you have already got in the results section once again in the discussion section in detail. (错)8.2.21. An effective way to develop your discussion section is to _____. () acknowledge the limitations2. An effective writing style of limitations in discussion section is to assess the impact of each limitation. (对)8.2.31. All Discussion sections are analytical, but not descriptive.对8.2.41. When we want to interpret the results, which tense is preferred? () past tense2. In this lecture , we mainly focus on the following aspects: (全选)tense voice diction第八章章节测试Discussion1. The discussion section can most effectively show your ability as a researcher to think critically about the issue studied. ()The discussion section can most effectively show your ability as a researcher to think critically about the issue studied. (对)2. The discussion section helps to engage the readers in thinking critically about issues based upon an evidence-based interpretation of findings.(对)3. It is not necessary to identify the relationship, patterns and corralations among the received data. (错)4. It is not necessary to discuss the reasons why you have got some unexpected data and defin their importance. (错)5. According the IMRAD format, discussion section is the _____ part of the body. () fourth6. Discussion section usually presents the underlying meaning of your research, which means_____?() Making the implications7. While we summarize the main findings in the discussion section, what should be done? () Present a comparison or a contrast with the published studies.8. Which of the following expression is true? () If access is denied or limited in some way , describe the reasons.9. When we focus on the discussion section, we mainly talk about the following elements?(全选) interpretation implication limitation and recommendation10. When discussing th limitations of your research, make sure to _____? (全选) explain why each limitation exists describe each limitation in detailed but concisely provide the reasons why each limitation could not be overcome9.11. The writing of introduction goes from specific to general, while the writing of conclusion goes from general to specific. (错)2. What would you do after evaluating the research results in conclusion?() restate the research purpose9.21. Present tense is often used by the author to restate the aim of the paper of tell readers his work done earlier. (错)2. The writers ought to ______ the major points already mentioned in the introduction of the synthesize第九章章节测试Conclusion1. You need to write a long and complex conclusion with enough details in order to make the paper appear professional。

3530 – Unit 3 Review Questions (TVM, Part 2) – Solutions1. Sambank offers you a loan that will require you to pay 6% interest compounded monthly. Which of the following is closest to the EAR charged by the bank?A) 5.84%B) 6.00%C) 6.17%D) 72.00%E) 6.48%Answer: CEAR = (1 + 0.06/12)12 - 1; 0.0617 or approx. 6.17%2. A homeowner wants to install a high efficiency water heater at a cost of $2,400. They are told the heater will produce all the hot water they want forever with no additional cost. How much must the homeowner save on water heating costs every year if this is to be a sound investment? Assume the required return on this investment is 9% per year.A) $216B) $240C) $248D) $262E) $220Answer: ACalculate the cash flow as the perpetuity where PV = C / r. PV = $2,400; C = $2,400 × 0.09 = $216 which is the annual cost savings.3. What is the APR on a loan with an effective annual rate of 15.01% and weekly compounding of interest? (There are 52 weeks in a year.)A) 13.00%B) 13.50%C) 14.00%D) 14.50%E) 14.95%Answer: CAPR/m = [(1 + EAR)^(1/m)] - 1 = [(1 + 0.1501)^(1/52)] - 1 = .002693weekly rateAPR = 0.002693 x 52 weeks = .140036 or 14.00%4. A bank lends some money to a business. The business will repay the bank a single payment ofrather than 8%?A) $7,341B) $35,892C) $76,033D) $83,374E) $18,000Answer: AUsing formula PV = FV/ (1 + r) ^ n or a calculator.FV = $180,000 I/Y = 8% N = 10; PV = $83,374.82; alternatively I/Y = 9%; PV = $76,033.95.Difference between the 2 PV’s = $7,340.885. You are considering an investment that will generate $10,000 in a year however this cash flow will decline at a rate of 8% per year forever. If the appropriate required return is 6%, then the value of this investment today is closest to:A) $71,429B) $500,000C) $166,667D) $41,667E) This problem cannot be solved.Answer: AExplanation: PV = C / r - g = $10,000 / (0.06 - (-0.08)) = 10,000 / 0.14 = $71,4296. How much would you have in four years if you deposit $5,000 at the beginning of each year for four years starting today. Interest is 10% compounded annually.A) $23,205.00B) $25,525.50C) $21,550.00D) $30,525.50E) $33,578.05Answer: BAnnuity Due: Using your calculator and set BGN buttonPMT=$5000 N= 4; I/Y =10%; PV=0; FV = $25,525.507. You have made an investment today of $3,000 that will pay you $125 per month over the next three years (36 payments) and you will receive your first payment today. What is the effective annual rate of return on this investment?A) 30.50%C) 35.15%D) 42.24%E) 44.32%Solution: CUsing your calculator…calculate the Periodic rate for an annuity “due”Given PV = $3,000; N = 36; PMT = $125 solve for I / Y = 2.5416%...then solve for EAR as follows EAR = [(1 + 0.025416 )^12] - 1 = 35.15%.8. You’ve invested money at Sambank that pays you monthly interest at an APR of 8%. You want to use this money to buy a car that will cost you $40,000 in 6 years. How much will you need to save every month starting a month from now to achieve your objective?A) $451.18B) $500.34C) $555.56D) $434.66E) $438.53Answer: DPeriod Rate Apr/m = 0.08/12 = 0.6667% per month = I/Y; FV = $40,000; N = 6 × 12 = 72; PV = 0.PMT = $434.669. The cash purchase cost of a photocopier is $42,000. You can also finance the purchase with 60 equal monthly installments at an APR of 6.5% starting one month from today. If after three years the company wishes to sell the photocopier, what is the minimum price for which they can sell the copier so they can pay off balance remaining on the loan?A) $18,448B) $19,645C) $19,842D) $26,813E) $17,946Answer: AMonthly int. rate of 6.5/12 = I/Y = 0.54%; PV = $42,000; N = 60 PMT = $821.79;PM of 24 months remaining payment keeping the interest rate unchanged. Using a financial calculator with N = 24, I/Y = 0.54%; PMT = $821.79; PV = $18,448.02.10. Donald and Melania are almost broke as Donald lost his job in November 2020. They are desperately trying to buy a small condo in Karmaland that requires a $150,000 mortgage. They are high risk borrowers so the VladP bank amortizes the mortgage over 20 years at a rate of 4.80%/yr (note interest is an APR compounded semi-annually) for a 5-year term with monthly payments. What is the principal owing on the mortgage after 5 years?B) $136,478C) $109,663D) $90,679E) $76,787Answer: AEAR = (1 + (0.0480/2))^2 – 1 = 4.8576%Period (monthly rate) APR/m = (1 + EAR / 12) ^12 -1 = 0.003961 or .3961%Solve for monthly payment using calculatorFV = 0; PV = 150,000; N = 240; I/Y=.3961%; PMT = $969.56The principal owing after five years means there are 15 years (180) payments still owing.N=180; I/Y = .3961%; PMT=969.60; PV = $124,62811. Five years ago you took out a $200,000 30 year mortgage with an APR of 6.5% (comp. semi-annually) with monthly payments. If you were to refinance the outstanding balance today with a 20 year mortgage with an APR of 4.25% (comp. semiannually) by how much would your monthly payment change?A) The monthly payment will increase by $98.33.B) The monthly payment will decrease by $98.33.C) The monthly payment will increase by $343.12.D) The monthly payment will decrease by $343.12.E) The monthly payment will decrease by $213.77.Answer: BCurrent mortgageEAR = (1 + 0.065/2)^2 - 1 = 6.606%; Monthly rate = (1 + 0.606) ^ (1/12) - 1 = 0.5345%,Given N = 360, I/Y = 0.5345% PV = 200,000, Solve for PMT = 1,252.85Mortgage Balance after 5 years N = 300, I/Y = 0.5345%, PMT = 1,252.85, PV = 187,035.67New mortgageEAR = (1 + 0.0425/2)^2 - 1 = 4.295%; Monthly rate = (1 + 0.4295) ^ (1/12) - 1 = 0.351%,New Mortgage Payment: N = 240, I/Y 0.351% PV = 187,035.67, Solve for PMT = 1,154.52Current Payment - New Payment = $1252.85 - $1154.52 = $98.33 decrease.12. Given an annual inflation rate of 3.24% a short-term investment offers a rate of 2.9% per annum, which of the following statements is correct?A) The purchasing power of investors in this investment will grow over the course of the year.B) The real interest rate for investors in this investment was greater than the rate of inflation.purchased at the start of the year.D) The nominal interest rate offered by this investment is the same as the real rate.E) Answers A & D are correct.Answer: C13. Assume your current mortgage payment is $900 per month. If you begin to pay $1,000 per month (with the extra $100 per month going to principal), which of the following will be TRUE?A) The mortgage balance will decrease faster with $1,000 monthly payments compared to $900 monthly payments.B) The total paid (principal and interest) will increase with $1,000 monthly payments compared to $900 monthly payments.C) The total interest expense will increase with $1,000 monthly payments compared to $900 monthly payments.D) The total principal paid will decrease with $1,000 monthly payments compared to $900 monthly payments.E) The time until your mortgage is paid off will increase with $1,000 monthly payments compared to $900 monthly payments.Answer: A14. Jumanji Dwayne wants to invest $5,000 for 5 years. The bank has many accounts for him to choose from. They are all different with respect to the APR rate and frequency of compounding; (annual, semiannual, quarterly, etc.). He should choose the account with…A) The highest APR.B) The highest EAR.C) The highest monthly rate.D) Daily compounding.E) The highest nominal rate.Answer: B。

Unit 3School LifeUnit Review基础过关全练Ⅰ.用括号内所给词的适当形式填空1.There is a big (different) between Chinese food and Indian food.2.If you are in a new place, a map will be very (help).3.These questions are very easy. I think I can answer them by ( I ).4.(2022黑龙江龙东地区中考)You’d better brush your teeth at least (two) a day.5.(2022甘肃临洮期中)Xiaoming (usual) works as a volunteer and visits the old people’s home at weekends.Ⅱ.单项选择6.(2022河北定州期中)—Who teaches you painting?—Nobody. I teach .A.meB.myselfC.youD.yourself7.You draw well, but please in my books.A.doesn’t drawB.not drawC.don’t drawD.draw not8.—You look sad. What ?—I lost my bike yesterday afternoon.A.startedB.finishedC.droppedD.happened9.—How often do you go to the cinema?—. I only watch movies at home.A.AlwaysB.OftenC.SometimesD.Never10.(2022甘肃武山四中期中)Smart Jim a good idea about how to finish the work better and faster.e up withB.came up withC.catches up withD.came upⅢ.连词成句11.school, how, life, your, going, is?12.up, always, gets, at 7:30 am, he.13.we, dance, in, free time, often, our.14.(2021河北雄县期中)in, sports, are, what, you, interested?15.they, go, do, how often, swimming? 能力提升全练Ⅳ.单项选择16.(2022广西贵港中考,35, ★☆☆)Tina gets up early every morning, so she is late for school.A.oftenB.alwaysuallyD.never17.(2022甘肃武山四中期中,16,★☆☆)Tony, write on the wall!A.notB.don’tC.doesn’tD.won’t18.(2021河北雄县期中,32,★☆☆)Look out, or there will be afire.fortableB.terribleC.boringD.friendly19.(2022甘肃临洮期中, 43, ★★☆)I can’t a good idea for cleaning my bedroom.e up withB.think aboute overe on20.(2021山东滨州中考,23,★★☆)—Dad, could you please teachEnglish?—Sure! But it’s more important to learn it by .A.my;yourselfB.my;youC.me;youD.me;yourselfⅤ.词语运用(2022河北雄县三月月考,★★☆)根据短文内容及所给提示,在空白处填写一个适当的单词或括号内单词的正确形式。

Chapter 3Consumer BehaviorQuestions for Review1. What are the four basic assumptions about individual preferences? Explain the significance ormeaning of each.(1) Preferences are complete: this means that the consumer is able to compare and rank all possiblebaskets of goods and services. (2) Preferences are transitive: this means that preferences are consistent, in the sense that if bundle A is preferred to bundle B and bundle B is preferred to bundle C, then bundleA is preferred to bundle C. (3) More is preferred to less: this means that all goods are desirable, andthat the consumer always prefers to have more of each good. (4) Diminishing marginal rate ofsubstitution: this means that indifference curves are convex, and that the slope of the indifference curve increases (becomes less negative) as we move down along the curve. As a consumer moves down along her indifference curve she is willing to give up fewer units of the good on the vertical axis in exchange for one more unit of the good on the horizontal axis. This assumption also means that balanced market baskets are generally preferred to baskets that have a lot of one good and very little of the other good.2. Can a set of indifference curves be upward sloping? If so, what would this tell you about thetwo goods?A set of indifference curves can be upward sloping if we violate assumption number three: more ispreferred to less. When a set of indifference curves is upward sloping, it means one of the goods is a “bad” so that the consumer pref ers less of that good rather than more. The positive slope means that the consumer will accept more of the bad only if he also receives more of the other good in return. As we move up along the indifference curve the consumer has more of the good he likes, and also more of the good he does not like.3. Explain why two indifference curves cannot intersect.The figure below shows two indifference curves intersecting at point A. We know from the definition of an indifference curve that the consumer has the same level of utility for every bundle of goods that lies on the given curve. In this case, the consumer is indifferent between bundles A and B because they both lie on indifference curve U1. Similarly, the consumer is indifferent between bundles A and C because they both lie on indifference curve U2. By the transitivity of preferences this consumer should also be indifferent between C and B. However, we see from the graph that C lies above B, so C must be preferred to B because C contains more of Good Y and the same amount of Good X as does B, and more is preferred to less. But this violates transitivity, so indifference curves must not intersect.Copyright © 2013 Pearson Education, Inc. Publishing as Prentice Hall.32 Pindyck/Rubinfeld, Microeconomics, Eighth EditionCopyright © 2013 Pearson Education, Inc. Publishing as Prentice Hall.4. Jon is always willing to trade one can of Coke for one can of Sprite, or one can of Sprite for onecan of Coke.a. What can you say about Jon’s marginal rate of substitution?Jon’s marginal rate of substitution can be defined as the number of cans of Coke he would bewilling to give up in exchange for a can of Sprite. Since he is always willing to trade one for one, his MRS is equal to 1.b. Draw a set of indifference curves for Jon.Since Jon is always willing to trade one can of Coke for one can of Sprite, his indifference curves are linear with a slope of -1. See the diagrams below part c.c. Draw two budget lines with different slopes and illustrate the satisfaction-maximizing choice.What conclusion can you draw?J on’s indifference curves are linear with a slope of -1. Jon’s budget line is also linear, and will have a slope that reflects the ratio of the two prices. If Jon’s budget line is steeper than his indifference curves, he will choose to consume only the good on the vertical axis. If Jon’s budget line is flatter than his indifference curves, he will choose to consume only the good on the horizontal axis. Jon will always choose a corner solution where he buys only the less expensive good, unless his budget line has the same slope as his indifference curves. In this case any combination of Sprite and Cokethat uses up his entire income will maximize Jon’s satisfaction.The diagrams below show cases where Jon’s budget line is steeper than his indifference curvesand where it is flatter. Jon’s indifference curves are linear with slopes of -1, and four indifferencecurves are shown in each diagram as solid lines. Jon’s budget is $4.00. In the diagram on the left, Coke costs $1.00 and Sprite costs $2.00, so Jon can afford 4 Cokes (if he spends his entire budget on Coke) or 2 Sprites (if he spends his budget on Sprite). His budget line is the dashed line. Thehighest indifference curve he can reach is the one furthest to the right. He can reach that level ofutility by purchasing 4 Cokes and no Sprites. In the diagram on the right, the price of Coke is $2.00 and the price of Sprite is $1.00. Jon’s budget line is now flatter than his indifference curves, andhis optimal bundle is the corner solution with 4 Sprites and no Cokes.Chapter 3Consumer Behavior335. What happens to the marginal rate of substitution as you move along a convex indifferencecurve? A linear indifference curve?The MRS measures how much of a good you are willing to give up in exchange for one more unit of the other good, keeping utility constant. The MRS diminishes along a convex indifference curve.This occurs because as you move down along the indifference curve, you are willing to give up less and less of the good on the vertical axis in exchange for one more unit of the good on the horizontal axis. The MRS is also the negative of the slope of the indifference curve, which decreases (becomes closer to zero) as you move down along the indifference curve. The MRS is constant along a linear indifference curve because the slope does not change. The consumer is always willing to trade the same number of units of one good in exchange for the other.6. Explain why an MRS between two goods must equal the ratio of the price of the goods for theconsumer to achieve maximum satisfaction.The MRS describes the rate at which the consumer is willing to trade off one good for another to maintain the same level of satisfaction. The ratio of prices describes the trade-off that the consumer is able to make between the same two goods in the market. The tangency of the indifference curve with the budget line represents the point at which the trade-offs are equal and consumer satisfaction is maximized. If the MRS between two goods is not equal to the ratio of prices, then the consumer could trade one good for another at market prices to obtain higher levels of satisfaction. For example, if the slope of the budget line (the ratio of the prices) is 4, the consumer can trade 4 units of Y(the good on the vertical axis) for one unit of X (the good on the horizontal axis). If the MRS at the current bundle is 6, then the consumer is willing to trade 6 units of Y for one unit of X. Since the two slopes are not equal the consumer is not maximizing her satisfaction. The consumer is willing to trade 6 but only has to trade 4, so she should make the trade. This trading continues until the highest level of satisfaction is achieved. As trades are made, the MRS will change and eventually become equal to the price ratio.7. Describe the indifference curves associated with two goods that are perfect substitutes. What ifthey are perfect complements?Two goods are perfect substitutes if the MRS of one for the other is a constant number. In this case, the slopes of the indifference curves are constant, and the indifference curves are therefore linear. If two goods are perfect complements, the indifference curves are L-shaped. In this case the consumer wants to consume the two goods in a fixed proportion, say one unit of good 1 for every one unit of good 2. If she has more of one good than the other, she does not get any extra satisfaction from the additional units of the first good.8. What is the difference between ordinal utility and cardinal utility? Explain why the assumptionof cardinal utility is not needed in order to rank consumer choices.Ordinal utility implies an ordering among alternatives without regard for intensity of preference. For example, if the c onsumer’s first choice is preferred to his second choice, then utility from the first34Pindyck/Rubinfeld, Microeconomics,Eighth Editionchoice will be higher than utility from the second choice. How much higher is not important. An ordinal utility function generates a ranking of bundles and no meaning is given to the magnitude of the utility number itself. Cardinal utility implies that the intensity of preferences may be quantified, and that the utility number itself has meaning. An ordinal ranking is all that is needed to rank consumer choices. It is not necessary to know how intensely a consumer prefers basket A over basket B; it is enough to know that A is preferred to B.9. Upon merging with the West German economy, East German consumers indicated a preferencefor Mercedes-Benz automobiles over Volkswagens. However, when they converted their savings into deutsche marks, they flocked to Volkswagen dealerships. How can you explain thisapparent paradox?There is no paradox. Preferences do not involve prices, and East German consumers preferredMercedes based solely on product characteristics. However, Mercedes prices are considerablyhigher than Volkswagen prices. So, even though East German consumers preferred a Mercedes to a Volkswagen, they either could not afford a Mercedes or they preferred a bundle of other goods plus a Volkswagen to a Mercedes alone. While the marginal utility of consuming a Mercedes exceeded the marginal utility of consuming a Volkswagen, East German consumers considered the marginal utility per dollar for each good and, for most of them, the marginal utility per dollar was higher forVolkswagens. As a result, they flocked to Volkswagen dealerships to buy VWs.10. Draw a budget line and then draw an indifference curve to illustrate the satisfaction-maximizing choice associated with two products. Use your graph to answer the followingquestions.a. Suppose that one of the products is rationed. Explain why the consumer is likely to beworse off.When goods are not rationed, the consumer is able to choose the satisfaction-maximizing bundle where the slope of the budget line is equal to the slope of the indifference curve, or the price ratio is equal to the MRS. This is point A in the diagram below where the consumer buys G1 of good 1 and G2 of good 2 and achieves utility level U2. If good 1 is now rationed at G* the consumer will no longer be able to attain the utility maximizing point. He or she cannot purchase amounts ofgood 1 exceeding G*. As a result, the consumer will have to purchase more of the othergood instead. The highest utility level the consumer can achieve with rationing is U1 at point B.This is not a point of tangency, and the consumer’s utility is lower than at point A, so theconsumer is worse off as a result of rationing.Copyright © 2013 Pearson Education, Inc. Publishing as Prentice Hall.Chapter 3Consumer Behavior35b. Suppose that the price of one of the products is fixed at a level below the current price. As aresult, the consumer is not able to purchase as much as she would like. Can you tell if theconsumer is better off or worse off?No, the consumer could be better off or worse off. When the price of one good is fixed at alevel below the current (equilibrium) price, there will be a shortage of that good, and the goodwill be effectively rationed. In the diagram below, the price of good 1 has been reduced, and theconsumer’s budget line has rotated out to the right. The consumer would like to purchase bundle B, but the amount of good 1 is restricted because of a shortage. If the most the consumer can purchase is G*, she will be exactly as well off as before, because she will be able to purchase bundle C on her original indifference curve. If there is more than G* of good 1 available, the consumer will bebetter off, and if there is less than G*, the consumer will be worse off.11. Describe the equal marginal principle. Explain why this principle may not hold if increasingmarginal utility is associated with the consumption of one or both goods.The equal marginal principle states that to obtain maximum satisfaction the ratio of the marginal utility to price must be equal across all goods. In other words, utility maximization is achieved when the budget is allocated so that the marginal utility per dollar of expenditure (MU/P) is the same for each good. If the MU/P ratios are not equal, allocating more dollars to the good with the higher MU/P will increase utility. As more dollars are allocated to this good its marginal utility will decrease,which causes its MU/P to fall and ultimately equal that of the other goods.If marginal utility is increasing, however, allocating more dollars to the good with the larger MU/P causes MU to increase, and that good’s MU/P just keeps getting larger and larger. In this case, the36Pindyck/Rubinfeld, Microeconomics,Eighth Editionconsumer should spend all her income on this good, resulting in a corner solution. With a corner solution, the equal marginal principle does not hold.12. The price of computers has fallen substantially over the past two decades. Use this drop in priceto explain why the Consumer Price Index is likely to overstate substantially the cost-of-living index for individuals who use computers intensively.The Consumer Price Index measures the cost of a basket of goods purchased by a typical consumer in the current year relative to the cost of the basket in the base year. Each good in the basket is assigneda weight, which reflects the importance of the good to the typical consumer, and the weights arekept fixed from year to year. One problem with fixing the weights is that consumers will shift their purchases from year to year to give more weight to goods whose prices have fallen, and less weight to goods whose prices have risen. The CPI will therefore give too much weight to goods whoseprices have risen, and too little weight to goods whose prices have fallen. In addition, for non-typical individuals who use computers intensively, the fixed weight for computers in the basket will understate the importance of this good, and will hence understate the effect of the fall in the price of computers for these individuals. The CPI will overstate the rise in the cost of living for this type of individual.13. Explain why the Paasche index will generally understate the ideal cost-of-living index.The Paasche index measures the current cost of the current bundle of goods relative to the base year cost of the current bundle of goods. The Paasche index will understate the ideal cost-of-living index because it assumes the individual buys the current year bundle in the base period. In reality, at base year prices the consumer would have been able to attain the same level of utility at a lower cost by altering his or her consumption bundle in light of the base year prices. Since the base year cost is overstated, the denominator of the Paasche index will be too large and the index will be too low, or understated.Exercises1. In this chapter, consumer preferences for various commodities did not change during theanalysis. In some situations, however, preferences do change as consumption occurs.Discuss why and how preferences might change over time with consumption of these twocommodities:a. CigarettesThe assumption that preferences do not change is a reasonable one if choices are independentacross time. It does not hold, however, when “habit-forming” or addictive behavior is involved,as in the case of cigarettes. The consumpt ion of cigarettes in one period influences the consumer’spreference for cigarettes in the next period: the consumer desires cigarettes more because he hasbecome more addicted to them.b. Dinner for the first time at a restaurant with a special cuisineThe first time you eat at a restaurant with a special cuisine can be an exciting new diningexperience. This may make eating at the restaurant more desirable. But once you’ve eaten there,it isn’t so exciting to do it again (“been there, done that”), and pre ference changes. On the otherhand, some people prefer to eat at familiar places where they don’t have to worry about new and unknown cuisine. For them, the first time at the restaurant would be less pleasant, but once they’veeaten there and discovered they like the food, they would find further visits to the restaurant more desirable. In both cases, preferences change as consumption occurs.Copyright © 2013 Pearson Education, Inc. Publishing as Prentice Hall.Chapter 3Consumer Behavior37 2. Draw indifference curves that represent the following individuals’ preferences for hamburgersand soft drinks. I ndicate the direction in which the individuals’ satisfaction (or utility) isincreasing.a. Joe has convex preferences and dislikes both hamburgers and soft drinks.Since Joe dislikes both goods, he prefers less to more, and his satisfaction is increasing in thedirection of the origin. Convexity of preferences implies his indifference curves will have thenormal shape in that they are bowed towards the direction of increasing satisfaction. Convexity also implies that given any two bundles between which the Joe is indifferent, any linear combination of the two bundles will be in the preferred set, or will leave him at least as well off. This is true of the indifference curves shown in the diagram below.b. Jane loves hamburgers and dislikes soft drinks. If she is served a soft drink, she will pour itdown the drain rather than drink it.Since Jane can freely dispose of the soft drink if it is given to her, she considers it to be a neutral good. This means she does not care about soft drinks one way or the other. With hamburgers on the vertical axis, her indifference curves are horizontal lines. Her satisfaction increases in theupward direction.c. Bob loves hamburgers and dislikes soft drinks. If he is served a soft drink, he will drink it tobe polite.Since Bob will drink the soft drink in order to be polite, it can be thought of as a “bad.” Whenserved another soft drink, he will require more hamburgers at the same time in order to keep his satisfaction constant. More soft drinks without more hamburgers will worsen his utility. Morehamburgers and fewer soft drinks will increase his utility, so his satisfaction increases as wemove upward and to the left.38 Pindyck/Rubinfeld, Microeconomics, Eighth EditionCopyright © 2013 Pearson Education, Inc. Publishing as Prentice Hall.d. Molly loves hamburgers and soft drinks, but insists on consuming exactly one soft drink forevery two hamburgers that she eats.Molly wants to consume the two goods in a fixed proportion so her indifference curves areL-shaped. For a fixed amount of one good, she gets no extra satisfaction from having more of theother good. She will only increase her satisfaction if she has more of both goods.e. Bill likes hamburgers, but neither likes nor dislikes soft drinks.Like Jane, Bill considers soft drinks to be a neutral good. Since he does not care about soft drinks one way or the other we can assume that no matter how many he has, his utility will be the same. His level of satisfaction depends entirely on how many hamburgers he has, so his satisfactionincreases in the upward direction only.f. Mary always gets twice as much satisfaction from an extra hamburger as she does from anextra soft drink.How much extra satisfaction Mary gains from an extra hamburger or soft drink tells us something about the marginal utilities of the two goods and about her MRS . If she always receives twice the satisfaction from an extra hamburger then her marginal utility from consuming an extra hamburger is twice her marginal utility from consuming an extra soft drink. Her MRS , with hamburgers onthe vertical axis, is 1/2 because she will give up one hamburger only if she receives two softdrinks. Her indifference curves are straight lines with a slope of 1/2.Chapter 3 Consumer Behavior 393. If Jane is currently willing to trade 4 movie tickets for 1 basketball ticket, then she must likebasketball better than movies. True or false? Explain.This statement is not necessarily true. If she is always willing to trade 4 movie tickets for 1 basketball ticket then yes, she likes basketball better because she will always gain the same satisfaction from 4 movie tickets as she does from 1 basketball ticket. However, it could be that she has convex preferences (diminishing MRS ) and is at a bundle where she has a lot of movie tickets relative to basketball tickets. As she gives up movie tickets and acquires more basketball tickets, her MRS will fall. If MRS falls far enough she might get to the point where she would require, say, two basketball tickets to give up another movie ticket. It would not mean though that she liked basketball better, just that she had a lot of basketball tickets relative to movie tickets. Her willingness to give up a good depends on the quantity of each good in her current basket.4. Janelle and Brian each plan to spend $20,000 on the styling and gas mileage features of a new car.They can each choose all styling, all gas mileage, or some combination of the two. Janelle does not care at all about styling and wants the best gas mileage possible. Brian likes both equally and wants to spend an equal amount on each. Using indifference curves and budget lines, illustrate the choice that each person will make.Plot thousands of dollars spent on styling on the vertical axis and thousands spent on gas mileage on the horizontal axis as shown above. Janelle, on the left, has indifference curves that are vertical. If the styling is there she will take it, but she otherwise does not care about it. As her indifference curves move over to the right, she gains more gas mileage and more satisfaction. She will spend all $20,000 on gas mileage at point J . Brian, on the right, has indifference curves that are L-shaped. He will not spend more on one feature than on the other feature. He will spend $10,000 on styling and $10,000 on gas mileage. His optimal bundle is at point B .5. Suppose that Bridget and Erin spend their incomes on two goods, food (F ) and clothing (C ).Bridget’s preferences are repres ented by the utility function (,)10U F C FC =, while Erin’spreferences are represented by the utility function 22(,)0.20U F C F C =.40 Pindyck/Rubinfeld, Microeconomics, Eighth EditionCopyright © 2013 Pearson Education, Inc. Publishing as Prentice Hall. a. With food on the horizontal axis and clothing on the vertical axis, identify on a graph the setof points that give Bridget the same level of utility as the bundle (10,5). Do the same forErin on a separate graph.The bundle (10,5) contains 10 units of food and 5 of clothing. Bridget receives a utility of10(10)(5) = 500 from this bundle. Thus, her indifference curve is represented by the equation10FC = 500 or C = 50/F . Some bundles on this indifference curve are (5,10), (10,5), (25,2),and (2,25). It is plotted in the diagram below. Erin receives a utility of 0.2(102)(52) = 500 fromthe bundle (10,5). Her indifference curve is represented by the equation 0.2F 2C 2 = 500, or C =50/F . This is the same indifference curve as Bridget. Both indifference curves have the normal,convex shape.b. On the same two graphs, identify the set of bundles that give Bridget and Erin the samelevel of utility as the bundle (15,8).For each person, plug F = 15 and C = 8 into their respective utility functions. For Bridget, thisgives her a utility of 1200, so her indifference curve is given by the equation 10FC = 1200, orC = 120/F . Some bundles on this indifference curve are (12,10), (10,12), (3,40), and (40,3). Theindifference curve will lie above and to the right of the curve diagrammed in part a. This bundlegives Erin a utility of 2880, so her indifference curve is given by the equation 0.2F 2C 2 = 2880, orC = 120/F . This is the same indifference curve as Bridget.c. Do you think Bridget and Erin have the same preferences or different preferences? Explain.They have the same preferences because their indifference curves are identical. This means theywill rank all bundles in the same order. Note that it is not necessary that they receive the samelevel of utility for each bundle to have the same set of preferences. All that is necessary is thatthey rank the bundles in the same order.6. Suppose that Jones and Smith have each decided to allocate $1000 per year to an entertainmentbudget in the form of hockey games or rock concerts. They both like hockey games and rock concerts and will choose to consume positive quantities of both goods. However, they differ substantially in their preferences for these two forms of entertainment. Jones prefers hockey games to rock concerts, while Smith prefers rock concerts to hockey games.a. Draw a set of indifference curves for Jones and a second set for Smith.Given they each like both goods and they will each choose to consume positive quantities of both goods, we can assume their indifference curves have the normal convex shape. However sinceJones has an overall preference for hockey and Smith has an overall preference for rock concerts, their two sets of indifference curves will have different slopes. Suppose that we place rock concerts on the vertical axis and hockey games on the horizontal axis, Jones will have a larger MRS thanSmith. Jones is willing to give up more rock concerts in exchange for a hockey game since heprefers hockey games. Thus, indifference curves for Jones will be steeper than the indifferencecurves for Smith.b. Using the concept of marginal rate of substitution, explain why the two sets of curves aredifferent from each other.At any combination of hockey games and rock concerts, Jones is willing to give up more rock concerts for an additional hockey game, whereas Smith is willing to give up fewer rock concerts for an additional hockey game. Since the MRS is a measure of how many of one good (rock concerts) an individual is willing to give up for an additional unit of the other good (hockey games), the MRS , and hence the slope of the indifference curves, will be different for the two individuals.7. The price of DVDs (D ) is $20 and the price of CDs (C ) is $10. Philip has a budget of $100 to spend on the two goods. Suppose that he has already bought one DVD and one CD. In addition there are 3 more DVDs and 5 more CDs that he would really like to buy.a. Given the above prices and income, draw his budget line on a graph with CDs on the horizontal axis.His budget line is +=D C P D P C I , or 20D + 10C = 100. If he spends his entire income on DVDs he can afford to buy 5. If he spends his entire income on CDs he can afford to buy 10. His budget line is linear with these two points as intercepts.b. Considering what he has already purchased and what he still wants to purchase, identify the three different bundles of CDs and DVDs that he could choose. For this part of the question, assume that he cannot purchase fractional units.He has already purchased one of each for a total of $30, so he has $70 left. Since he wants 3 more DVDs, he can buy these for $60 and spend his remaining $10 on 1 CD. This is the first bundle below. He could also choose to buy only 2 DVDs for $40 and spend the remaining $30 on 3 CDs. This is the second bundle. Finally, he could purchase 1 more DVD for $20 and spend the remaining $50 on the 5 CDs he would like. This is the final bundle shown in the table below.Purchased Quantities Total Quantities DVDsCDs DVDs CDs 31 42 23 34 15 2 68. Anne has a job that requires her to travel three out of every four weeks. She has an annual travel budget and can travel either by train or by plane. The airline on which she typically flies has a frequent-traveler program that reduces the cost of her tickets according to the number of miles she has flown in a given year. When she reaches 25,000 miles, the airline will reduce the price of her tickets by 25% for the remainder of the year. When she reaches 50,000 miles, the airline will reduce the price by 50% for the remainder of the year. Graph Anne’s budget line, with train miles on the vertical axis and plane miles on the horizontal axis.The typical budget line is linear (with a constant slope) because prices do not change. In this case, the price of airline miles changes depending on how many miles Anne purchases. As the price changes, the slope of the budget line changes. Because there are three prices, there will be three slopes (and two kinks) to the budget line. Since the price falls as Anne flies more miles, her budget line will become flatter with each price change.。

冀教版（三年级起始版）《小学英语》Book 5 Unit 3Again, please!一、教材分析1．学习内容分析本课是复习Li M ing和他的朋友到北京旅行的内容，以人物的活动为主线，围绕最常用、最基本的英语词汇、句型、交际会话等逐步展开。

会话内容和句型均十分贴近学生的实际，可创设真实的语言情景，最大限度的来调动学生的积极性，从而激发学生的学习兴趣，为进一步学习打下基础。

2．学生分析教学对象为五年级学生，学生已学习了本单元的单词和句型，有了一些相关的知识储备，很乐于丰富自己的英语词汇，而且喜欢表演，乐于展示自我。

本课通过一些任务活动，使其掌握所学，并灵活运用。

二、教学目标：语言知识目标：本单元重点词汇about, train, airplane, faster, slower, leave 和句型How far is it? How do you want to go? When do you leave/arrive?语言技能目标：a．学生能正确地听、说、读、写本单元重点单词。

b. 能熟练运用所学句型谈论关于旅行的话题。

情感态度目标：激发学生学习英语的兴趣，引导学生在学习过程中体验成功，感受快乐，树立自信心。

学习策略目标：通过小组活动，培养学生积极与他人合作，共同完成学习任务。

文化意识目标：通过情景会话、短剧表演等了解我国和世界上主要国家的名胜及重要标志物，培养学生的跨文化意识。

三、教学重、难点：本单元重点词汇和How far is it? It’s about…kilometers.运用。

四、教学准备：多媒体课件五、教学过程：六、教学反思：本单元是一个按照事情发展叙述的小故事，连续性较强，因此我按照LiMing and his mother want to go on a trip to Beijing. How do they want to go? Who do they want to invite? When do they leave? 这一主线复习本单元内容，并穿插了两首英文歌曲辅助教学，首先在导入环节里利用歌曲How do you want to go?不仅营造了课堂气氛，还引出交通工具单词并比较快慢复习faster than 和slower than, 让学生结合日常生活实际比出各种交通工具的快慢，培养学生自主意识。