最新06级数据库A卷

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2006数据库试卷_含答案

广东工业大学试卷用纸，第 3 页共7页18、下列聚合函数中不忽略空值(NULL)的是 CA) SUM(金额) B) MAX(成绩)C) COUNT(*) D) AVG(成绩)19、现有借阅关系表：借阅（书号，书名，库存数，读者号，借期，还期），假如同一本书允许一个读者多次借阅，但不能同时对一种书借多本。

则该关系模式的键是 DA) 书号B) 读者号C) 书号，读者号D) 书号，读者号，借期20、关系数据模型的三要素中不包括 CA）完整性规则B）数据结构C）恢复D）数据操作二、问答题（共22分）1、什么是数据的独立性？数据库系统中为什么能具有数据独立性？(8分)答：数据的独立性是指逻辑独立性和物理独立性。

(2分)数据的逻辑独立性是指当数据的总体逻辑结构改变时，数据的局部逻辑结构不变，由于应用程序是依据数据的局部逻辑结构编写的，所以应用程序不必须修改，从而保证了数据与程序间的逻辑独立性(1分)。

数据的物理独立性是指当数据的存储结构改变时，数据的逻辑结构不变，从而应用程序也不必改变(1分)。

原因：1）内模式映象保证了数据的物理独立性，如存储结构变化时，模式/内模式映象也应有相应的变化，使其概念模式仍保持不变，即把存储结构的变化的影响限制在概念模式之下，这使数据的存储结构和存储方法较高的独立于应用程序，通过映象功能保证数据存储结构的变化不影响数据的全局逻辑结构的改变，从而不必修改应用程序，即确保了数据的物理独立性。

(2分)2）外模式/模式映象保证了数据的逻辑独立性。

该级保证了数据的局部逻辑结构不变，由于应用程序是依据数据的局部逻辑结构编写的，所以应用程序不必须修改，从而保证了数据与程序间的逻辑独立性。

(2分)2、简述关系数据库中基本表的6个性质。

(7分)答：1、同一关系中各个属性具有同质性；2、同一关系中列顺序无关性3、同一关系中元组具有无冗余性；4、同一关系中，属性名具有唯一性；5、同一关系中，元组顺序具有无关性；6、关系中每一分量必须是不可分的数据项(1分)3、试述关系模型的完整性规则。

数据库06年考试

Fundamentals of Data StructuresMid-Term Exam1. Among the following data structures, is the best for random access of the elements in a linear list.(2 points).A. singly linked listB. doubly linked listC. arrayD. doubly linked circular list2. There are threads in a threaded binary tree with n nodes. (2 points)A. n– 1B. nC. n + 1D. n + 23. When open addressing is used to solve collisions, to delete a key from the hash table we must .(2 points)A.clear the cell that was occupied by the keyB.replace the key by a special value that signals the availability of the cellC.find all the keys that have the same hash value of this key and shift them by 1 cellD. replace the key by the last inserted key which has the same hash value of this key4. Given a string of expression, 3 * a +b/c. Please use a stack to give the sequence of operations which re-orders the expression into 3 a * b c / +. Here let P stand for “push” and “O” for “pop”. For example, ABC is re-ordered into BCA by PPOPOO. (7 points)5. Given a tree with n1 nodes of degree 1, n2 nodes of degree 2, ……, n m nodes of degree m. How manyleaf nodes does this tree have? (2 points)6. Given a list of integers {40, 30, 36, 77, 51, 32, 80}. Please insert these integers according to the givenorder into a binary search tree which is originally empty. Please draw the resulting binary search tree.（7 points）7. Given an array of the sequence { 12，70，33，65，24，56，48，92，86，35 }, please adjust the array intoa max heap. The resulting sequence is: (5 points)8. The inorder traversal sequence of some binary tree is given as 1234567, and its postorder sequence is2315764. Please draw this binary tree. (7 points)9. Please fill in the blanks in the program which finds Key from a hash table H with quadratic probing. (3points)Position Find ( ElementType Key, HashTable H ){ Position CurrentPos;int CollisionNum;CollisionNum = 0;CurrentPos = Hash( Key, H->TableSize );while( H->TheCells[ CurrentPos ].Info != Empty && ) {;if ( CurrentPos >= H->TableSize )CurrentPos - = H->TableSize;}Return CurrentPOs;}10. Please write a C program to delete all the nodes with key > x from a binary search tree. Here key and xare both integers between 1 and 100. Return TRUE if the deletion is successful or if there is nothing to be deleted, otherwise return FALSE. (8 points)typedef enum {FALSE, TRUE} Boolean;typedef struct node *tree_pointer;typedef struct node {int key;tree_pointer left_child, right_child;};Boolean delete_BST( tree_pointer *tree, int x )。

2006年6月17日大学英语六级(CET-6)真题试卷(A卷)及答案、听力原文

2006年6月17日大学英语六级(CET-6)真题试卷(A卷)注意事项一、将自己的校名、姓名、准考证号写在答题卡上。

将本试卷代号(A、B卷)划在答题卡上。

二、试卷和答题卡均不得带出考场。

考试结束，监考员收卷后考生才可离开。

三、仔细读懂题目的说明。

四、多项选择题的答案一定要划在答题卡上，凡是写在试卷上的答案一律无效。

每题只能选一个答案：如多选。

则该题无分，选定答案后，用铅笔在相应字母的中部划一条横线。

正确方法是：A) B) C) D)。

使用其他符号答题者不给分，划线要有一定粗度，浓度要盖过字母底色。

五、如果要改动答案，必须先用橡皮擦净原来选定的答案，然后再按上面的规定重新答题。

六、试题的第四部分改错(Error Correction)和第五部分作文(Writing)印刷在答题卡上，请用黑色字迹签字笔在答题卡上作答。

七、在90分钟内做完试题的第一至第四部分，90分钟后，监考员收取试卷，然后考生再做第五部分作文题，答题时间为30分钟。

全部考试时间为120分钟，不得拖延时间。

八、在考试过程中要注意对自己的答案保密，若被他人抄袭，一经发现，后果自负。

全国大学英语四、六级考试委员会Part I Listening Comprehension (20 minutes)Section ADirections: In this section, you will hear 10 short conversations. At the end of each conversation, a question will be asked about what was said. Both theconversation and the question will be spoken only once. After eachquestion there will be a pause. During the pause, you must read the fourchoices marked A), B), C) and D), and decide which is the best answer.Then mark the corresponding letter on the Answer Sheet with a single linethrough the centre.1. A) She met with Thomas just a few days ago.B) She can help with the orientation program.C) She is not sure she can pass on the message.D) She will certainly try to contact Thomas.2. A) Set the dinner table.B) Change the light bulb.C) Clean the dining room.D) Hold the ladder for him.3. A) He‟d like a piece of pie.B) He‟d like some coffee.C) He‟d rather stay in the warm room.D) He‟s just had dinner with his friends.4. A) He has managed to sell a number of cars.B) He is contented with his current position.C) He might get fired.D) He has lost his job.5. A) Tony‟s secretary.B) Paul‟s girlfriend.C) Paul‟s colleague.D) Tony‟s wife.6. A) He was fined for running a red light.B) He was caught speeding on a fast lane.C) He had to run quickly to get the ticket.D) He made a wrong turn at the intersection.7. A) He has learned a lot from his own mistakes.B) He is quite experienced in taming wild dogs.C) He finds reward more effective than punishment.D) He thinks it important to master basic training skills.8. A) At a bookstore.B) At the dentist‟s.C) In a restaurant.D) In the library.9. A) He doesn‟t want Jenny to get into trouble.B) He doesn‟t agree with the woman‟s remark.C) He thinks Jenny‟s workload too heavy at college.D) He believes most college students are running wild.10. A) It was applaudable.B) It was just terrible.C) The actors were enthusiastic.D) The plot was funny enough.Section BDirections: In this section, you will hear 3 short passages. At the end of each passage, you will hear some questions. Both the passage and the questions will bespoken only once. After you hear a question, you must choose the bestanswer from the four choices marked A), B), C) and D). Then mark thecorresponding letter on the Answer Sheet with a single line through thecentre.Passage OneQuestions 11 to 13 are based on the passage you have just heard.11. A) Social work.B) Medical care.C) Applied physics.D) Special education.12. A) The timely advice from her friends and relatives.B) The two-year professional training she received.C) Her determination to fulfill her dream.D) Her parents‟ consistent moral support.13. A) To get the funding for the hospitals.B) To help the disabled children there.C) To train therapists for the children there.D) To set up an institution for the handicapped.Passage TwoQuestions 14 to 17 are based on the passage you have just heard.14. A) At a country school in Mexico.B) In a mountain valley of Spain.C) At a small American college.D) In a small village in Chile.15. A) By expanding their minds and horizons.B) By financing their elementary education.C) By setting up a small primary school.D) By setting them an inspiring example.16. A) She wrote poetry that broke through national barriers.B) She was a talented designer of original school curriculums.C) She proved herself to be an active and capable stateswoman.D) She made outstanding contributions to children‟s education.17. A) She won the 1945 Nobel Prize in Literature.B) She was the first woman to win a Nobel Prize.C) She translated her books into many languages.D) She advised many statesmen on international affairs.Passage ThreeQuestions 18 to 20 are based on the passage you have just heard.18. A) How animals survive harsh conditions in the wild.B) How animals alter colors to match their surroundings.C) How animals protect themselves against predators.D) How animals learn to disguise themselves effectively.19. A) Its enormous size.B) Its plant-like appearance.C) Its instantaneous response.D) Its offensive smell.20. A) It helps improve their safety.B) It allows them to swim faster.C) It helps them fight their predators.D) It allows them to avoid twists and turns.Part II Reading Comprehension (35 minutes)Directions: There are 4 passages in this part. Each passage is followed by some questions or unfinished statements. For each of them there are four choicesmarked A), B), C) and D). You should decide on the best choice and markthe corresponding letter on the Answer Sheet with a single line through thecentre.Passage OneQuestions 21 to 25 are based on the following passage.There are good reasons to be troubled by the violence that spreads throughout the media. Movies, Television and video games are full of gunplay and bloodshed, and one might reasonably ask what‟s wrong with a society that presents videos of domestic violence as entertainment.Most researchers agree that the causes of real-world violence are complex. A 1993 study by the U.S. National Academy of Sciences listed “biological, individual, family, peer, school, and community factors” as all playing their parts.Viewing abnormally large amounts of violent television and video games may well contribute to violent behavior in certain individuals. The trouble comes when researchers downplay uncertainties in their studies or overstate the case for causality (因果关系). Skeptics were dismayed several years ago when a group of societies including the American Medical Association tried to end the debate by issuing a joint statement: “At this time, well over 1,000 studies... point overwhelmingly to a causal connection between media violence and aggressive behavior in some children.”Freedom-of-speech advocates accused the societies of catering to politicians, and even disputed the number of studies (most were review articles and essays, they said). When Jonathan Freedman, a social psychologist at the University of Toronto, reviewed the literature, he found only 200 or so studies of television-watching and aggression. And when he weeded out “the most doubtful measures of aggression”, only 28% supported a connection.The critical point here is causality. The alarmists say they have proved that violent media cause aggression. But the assumptions behind their observations need to be examined. When labeling games as violent or non-violent, should a hero eating a ghost really be counted as a violent event? And when experimenters record the time it takes game players to read …aggressive‟ or …non-aggressive‟ words from a list, can we be sure what they are actually measuring? The intent of the new Harvard Center on Media and Child Health to collect and standardize studies of media violence in order to compare their methodologies, assumptions and conclusions is an important step in the right direction.Another appropriate step would be to tone down the criticism until we know more. Several researchers write, speak and testify quite a lot on the threat posed by violence in the media. That is, of course, their privilege. But when doing so, they often come out with statements that the matter has now been settled, drawing criticism from colleagues. In response, the alarmists accuse critics and news reporters of being deceived by the entertainment industry. Such clashes help neither science nor society.21. Why is there so much violence shown in movies, TV and video games?A) There is a lot of violence in the real world today.B) Something has gone wrong with today‟s society.C) Many people are fond of gunplay and bloodshed.D) Showing violence is thought to be entertaining.22. What is the skeptics (Line 3. Para. 3) view of media violence?A) Violence on television is a fairly accurate reflection of real-world life.B) Most studies exaggerate the effect of media violence on the viewers.C) A causal relationship exists between media and real-world violence.D) The influence of media violence on children has been underestimated.23. The author uses the term “alarmists” (Line 1. Para. 5) to refer to those who________.A) use standardized measurements in the studies of media violenceB) initiated the debate over the influence of violent media on realityC) assert a direct link between violent media and aggressive behaviorD) use appropriate methodology in examining aggressive behavior24. In refuting the alarmists, the author advances his argument by first challenging________.A) the source and amount of their dataB) the targets of their observationC) their system of measurementD) their definition of violence25. What does the author think of the debate concerning the relationship between themedia and violence?A) More studies should be conducted before conclusions are drawn.B) It should come to an end since the matter has now been settled.C) The past studies in this field have proved to be misleading.D) He more than agrees with the views held by the alarmists.Passage TwoQuestions 26 to 30 are based on the following passage.You‟re in trouble if you have to buy your own brand-name prescription drugs. Over the past decade, prices leaped by more than double the inflation rate. Treatments for chronic conditions can easily top $2,000 a month-no wonder that one in four Americans can‟s afford to fill their prescriptions. The solution? A hearty chorus of “O Canada.” North of the border, where price controls reign, those same brand-name drugs cost 50% to 80% less.The Canadian option is fast becoming a political wake-up call, “If our neighbors canbuy drugs at reasonable prices, why can‟t we? Even to whisper that thought provokes anger. “Un-American!” And-the propagandists‟trump card (王牌)—“Wreck our brilliant health-care system.” Supersize drug prices, they claim, fund the research that sparks the next generation of wonder drugs. No sky-high drug price today, no cure for cancer tomorrow. So shut up and pay up.Common sense tells you that‟s a false alternative. The reward for finding, say, a cancer cure is so huge that no one‟s going to hang it up. Nevertheless, if Canada-level pricing came to the United States, the industry‟s profit margins would drop and the pace of new-drug development would slow. Here lies the American dilemma. Who is all this splendid medicine for? Should our health-care system continue its drive toward the best of the best, even though rising numbers of patients can‟t afford it? Or should we direct our wealth toward letting everyone in on today‟s level of care? Measured by saved lives, the latter is almost certainly the better course.To defend their profits, the drug companies have warned Canadian wholesalers and pharmacies (药房) not to sell to Americans by mail, and are cutting back supplies to those who dare.Meanwhile, the administration is playing the fear card. Officials from the Food and Drug Administration will argue that Canadian drugs might be fake, mishandled, or even a potential threat to life.Do bad drugs fly around the Internet? Sure-and the more we look, the more we‟ll find, But I haven‟t heard of any raging epidemics among the hundreds of thousands of people buying crossborder.Most users of prescription drugs don‟t worry about costs a lot. They‟re sheltered by employee insurance, owing just a $20 co-pay. The financial blows rain, instead, on the uninsured, especially the chronically ill who need expensive drugs to live, This group will still include middle-income seniors on Medicare, who‟ll have to dig deeply into their pockets before getting much from the new drug benefit that starts in 2006.26. What is said about the consequence of the rocketing drug prices in the U.S.?A) A quarter of Americans can‟t afford their prescription drugs.B) Many Americans can‟t afford to see a doctor when they fall ill.C) Many Americans have to go to Canada to get medical treatment.D) The inflation rate has been more than doubled over the years.27. It can be inferred that America can follow the Canadian model and curb its soaringdrug prices by ________.A) encouraging people to buy prescription drugs onlineB) extending medical insurance to all its citizensC) importing low-price prescription drugs from CanadaD) exercising price control on brand-name drugs28. How do propagandists argue for the U.S. drug pricing policy?A) Low prices will affect the quality of medicines in America.B) High prices are essential to funding research on new drugs.C) Low prices will bring about the anger of drug manufacturers.D) High-price drugs are indispensable in curing chronic diseases.29. What should be the priority of America‟s health-care system according to theauthor?A) To resolve the dilemma in the health-care system.B) To maintain America‟s lead in the drug industry.C) To allow the vast majority to enjoy its benefits.D) To quicken the pace of new drug development.30. What are American drug companies doing to protect their high profits?A) Labeling drugs bought from Canada as being fakes.B) Threatening to cut back funding for new drug research.C) Reducing supplies to uncooperative Canadian pharmacies.D) Attributing the raging epidemics to the ineffectiveness of Canadian drugs.Passage ThreeQuestions 31 to 35 are based on the following passage.Age has its privileges in America. And one of the more prominent of them is the senior citizen discount. Anyone who has reached a certain age—in some cases as low as 55—is automatically entitled to a dazzling array of price reductions at nearly every level of commercial life. Eligibility is determined not by one‟s need but by the date on one‟s birth certificate. Practically unheard of a generation ago, the discounts have become a routine part of many businesses—as common as color televisions in motel rooms and free coffee on airliners.People with gray hair often are given the discounts without even asking for them；yet, millions of Americans above age 60 are healthy and solvent (有支付能力的). Businesses that would never dare offer discounts to college students or anyone under 30 freely offer them to older Americans. The practice is acceptable because of the widespread belief that “elderly”and “needy”are synonymous (同义的). Perhaps that once was true, but today elderly Americans as a group have a lower poverty rate than the rest of the population. To be sure, there is economic diversity within the elderly, and many older Americans are poor, But most of them aren‟t.It is impossible to determine the impact of the discounts on individual companies. For many firms, they are a stimulus to revenue. But in other cases the discounts are given at the expense, directly or indirectly, of younger Americans. Moreover, they are a direct irritant in what some politicians and scholars see as a coming conflict between thegenerations.Generational tensions are being fueled by continuing debate over Social Security benefits, which mostly involves a transfer of resources from the young to the old. Employment is another sore point, Buoyed (支持) by laws and court decisions, more and more older Americans are declining the retirement dinner in favor of staying on the job-thereby lessening employment and promotion opportunities for younger workers.Far from a kind of charity they once were, senior citizen discounts have become a formidable economic privilege to a group with millions of members who don‟t need them.It no longer makes sense to treat the elderly as a single group whose economic needs deserve priority over those of others. Senior citizen discounts only enhance the myth that older people can‟t take care of themselves and need special treatment；and they threaten the creation of a new myth, that the elderly are ungrateful and taking for themselves at the expense of children and other age groups. Senior citizen discounts are the essence of the very thing older Americans are fighting against-discrimination by age.31. We learn from the first paragraph that ________.A) offering senior citizens discounts has become routine commercial practiceB) senior citizen discounts have enabled many old people to live a decent lifeC) giving senior citizens discounts has boosted the market for the elderlyD) senior citizens have to show their birth certificates to get a discount32. What assumption lies behind the practice of senior citizen discounts?A) Businesses, having made a lot of profits, should do something for society inreturn.B) Old people are entitled to special treatment for the contribution they made tosociety.C) The elderly, being financially underprivileged, need humane help from society.D) Senior citizen discounts can make up for the inadequacy of the Social Securitysystem.33. According to some politicians and scholars, senior citizen discounts will ________.A) make old people even more dependent on societyB) intensify conflicts between the young and the oldC) have adverse financial impact on business companiesD) bring a marked increase in the companies revenues34. How does the author view the Social Security system?A) It encourages elderly people to retire in time.B) It opens up broad career prospects for young people.C) It benefits the old at the expense of the young.D) It should be reinforced by laws and court decisions.35. Which of the following best summarizes the author‟s main argument?A) Senior citizens should fight hard against age discrimination.B) The elderly are selfish and taking senior discounts for granted.C) Priority should be given to the economic needs of senior citizens.D) Senior citizen discounts may well be a type of age discrimination.Passage FourQuestions 36 to 40 are based on the following passage.In 1854 my great-grandfather, Morris Marable, was sold on an auction block in Georgia for $500. For his white slave master, the sale was just “business as usual.” But to Morris Marable and his heirs, slavery was a crime against our humanity. This pattern of human rights violations against enslaved African-Americans continued under racial segregation for nearly another century.The fundamental problem of American democracy in the 21st century is the problem of “structural racism” the deep patterns of socio-economic inequality and accumulated disadvantage that are coded by race, and constantly justified in public speeches by both racist stereotypes and white indifference. Do Americans have the capacity and vision to remove these structural barriers that deny democratic rights and opportunities to millions of their fellow citizens?This country has previously witnessed two great struggles to achieve a truly multicultural democracy.The First Reconstruction (1865-1877) ended slavery and briefly gave black men voting rights, but gave no meaningful compensation for two centuries of unpaid labor. The promise of “40 acres and a mule (骡子)”was for most blacks a dream deferred (尚未实现的).The Second Reconstruction (1954-1968), or the modern civil rights movement, ended legal segregation in public accommodations and gave blacks voting rights. But these successes paradoxically obscure the tremendous human costs of historically accumulated disadvantage that remain central to black Americans‟ lives.The disproportionate wealth that most whites enjoy today was first constructed from centuries of unpaid black labor. Many white institutions, including some leading universities, insurance companies and banks, profited from slavery. This pattern of white privilege and black inequality continues today.Demanding reparations (赔偿) is not just about compensation for slavery and segregation. It is, more important, an educational campaign to highlight the contemporary reality of “racial deficits” of all kinds, the unequal conditions that impact blacks regardless of class. Structural racism‟s barriers include “equity inequity.” the absence of black capital formation that is a direct consequence of America‟s history. Onethird of all black households actually have negative net wealth. In 1998 the typical black family‟s net wealth was $16,400, less than one fifth that of white families. Black families are denied home loans at twice the rate of whites.Blacks remain the last hired and first fired during recessions. During the 1990-91 recession, African-Americans suffered disproportionately. At Coca-Cola, 42 percent of employees who lost their jobs were blacks. At Sears, 54 percent were black, Blacks have significantly shorter life spans, in part due to racism in the health establishment. Blacks are statistically less likely than whites to be referred for kidney transplants or early-stage cancer surgery.36. To the author, the auction of his great-grandfather is a typical example of ________.A) crime against humanityB) unfair business transactionC) racial conflicts in GeorgiaD) racial segregation in America37. The barrier to democracy in 21st century America is ________.A) widespread use of racist stereotypesB) prejudice against minority groupsC) deep-rooted socio-economic inequalityD) denial of legal rights to ordinary blacks38. What problem remains unsolved in the two Reconstructions?A) Differences between races are deliberately obscured.B) The blacks are not compensated for their unpaid labor.C) There is no guarantee for blacks to exercise their rights.D) The interests of blacks are not protected by law.39. It is clear that the wealth enjoyed by most whites ________.A) has resulted from business successes over the yearsB) has been accompanied by black capital formationC) has derived from sizable investments in educationD) has been accumulated from generations of slavery40. What does the author think of the current situation regarding racial discrimination?A) Racism is not a major obstacle to blacks‟ employment.B) Inequality of many kinds remains virtually untouched.C) A major step has been taken towards reparations.D) Little has been done to ensure blacks‟ civil rights.Part III Vocabulary (20 minutes)Directions: There are 30 incomplete sentences in this part. For each sentence there are four choices marked A), B), C) and D). Choose the ONE answer that bestcompletes the sentence. Then mark the corresponding letter on the AnswerSheet with a single line through the centre.41. Because of the ________ of its ideas, the book was in wide circulation both at homeand abroad.A) originalityB) subjectivityC) generalityD) ambiguity42. With its own parliament and currency and a common ________ for peace, theEuropean Union declared itself—in 11 official languages—open for business.A) inspirationB) assimilationC) intuitionD) aspiration43. America has now adopted more ________ European-style inspection systems, andthe incidence of food poisoning is falling.A) discreteB) solemnC) rigorousD) autonomous44. Mainstream pro-market economists all agree that competition is an ________ spurto efficiency and innovation.A) extravagantB) exquisiteC) intermittentD) indispensable45. In the late 19th century, Jules Verne, the master of science fiction, foresaw many ofthe technological wonders that are ________ today.A) transientB) commonplaceC) implicitD) elementary46. I was so ________ when I used the automatic checkout lane in the supermarket forthe first time.A) immersedB) assaultedC) thrilledD) dedicated47. His arm was ________ from the shark‟s mouth and reattached, but the boy, whonearly died, remained in a delicate condition.A) retrievedB) retainedC) repelledD) restored48. Bill Gates and Walt Disney are two people America has ________ to be the GreatestAmerican.A) appointedB) appeasedC) nicknamedD) dominated49. The ________ majority of citizens tend to believe that the death penalty will helpdecrease the crime rate.A) overflowingB) overwhelmingC) prevalentD) premium50. We will also see a ________ increase in the number of televisions per household, assmall TV displays are added to clocks, coffee makers and smoke detectors.A) startlingB) surpassingC) suppressingD) stacking51. The advance of globalization is challenging some of our most ________ values andideas, including our idea of what constitutes “home”.A) enrichedB) enlightenedC) cherishedD) chartered52. Researchers have discovered that ________ with animals in an active way maylower a person‟s blood pressure.A) interactingB) integratingC) migratingD) merging53. The Beatles, the most famous British band of the 1960s, traveled worldwide formany years, ________ cultural barriers.A) transportingB) transplantingC) transferringD) transcending54. In his last years, Henry suffered from a disease that slowly ________ him of muchof his sight.A) relievedB) jeopardizedC) deprivedD) eliminated55. Weight lifting, or any other sport that builds up your muscles, can make bonesbecome denser and less ________ to injury.A) attachedB) proneC) immuneD) reconciled56. He has ________ to museums hundreds of his paintings as well as his entirepersonal collection of modern art.A) ascribedB) attributedC) designatedD) donated57. Erik‟s website contains ________ photographs and hundreds of articles and shortvideos from his trip around the globe.A) prosperousB) gorgeousC) spaciousD) simultaneous58. Optimism is a ________ shown to be associated with good physical health, lessdepression and longer life.A) trailB) traitC) traceD) track59. The institution has a highly effective program which helps first-year students makea successful ________ into college life.A) transformationB) transmissionC) transitionD) transaction60. Philosophers believe that desire, hatred and envy are “negative emotions” which________ the mind and lead it into a pursuit of power and possessions.A) distortB) reinforceC) exertD) scramble61. The term “glass ceiling” was first used by the Wall Street Journal to describe theapparent barriers that prevent women from reaching the top of the corporate ________.A) seniorityB) superiorityC) heightD) hierarchy62. Various efforts have been made over the centuries to predict earthquakes, includingobserving lights in the sky and ________ animal behavior.A) abnormalB) exoticC) absurdD) erroneous63. Around 80 percent of the ________ characteristics of most white Britons have beenpassed down from a few thousand Ice Age hunters.A) intelligibleB) randomC) spontaneousD) genetic64. Picasso gained popularity in the mid-20th century, which was ________ of a newattitude towards modern art.A) informativeB) indicativeC) exclusiveD) expressive65. The country was an island that enjoyed civilized living for a thousand years or morewith little ________ from the outside world.A) disturbanceB) discriminationC) irritationD) irregularity66. Fashion designers are rarely concerned with vital things like warmth, comfort and________.A) stabilityB) capabilityC) durabilityD) availability67. Back in the days when people traveled by horse and carriage, Karl Benz ________the world with his extraordinary three-wheeled motor vehicle.A) inhibitedB) extinguishedC) quenchedD) stunned。

数据库原理试题05-06A卷答案

2005—2006学年第一学期期末考试试卷（A卷）一、单项选择题:在每小题的备选答案中选出一个正确答案，并将正确答案的代码填在题干上的括号内。

（每小题 1分，本大题共 10分）1．B 2．C 3．D 4．D 5．D 6．D 7．B 8．A9．B 10．A二、填空题:（每空1分，本大题共10分）1．数据库管理系统DBMS2．完整性约束3．选择运算4．DISTINCT5．获得权限的用户还能够获得传递权限，把获得的权限转授给其他用户6．1NF7．伪传递规则8．BCNF 3NF9．隔离性10．介质故障三、判断改正题:判断下列各题是否正确，正确的划√，错误的划×，并说明理由。

（每小题2分，本大题共10分）1．错误（1分）实体是指客观存在可以相互区别的事物，既可以是具体的对象，也可以是抽象的事件。

故“一个男生”和“一次借书”均为一个实体。

（1分）2．错误(1分)函数依赖不是指关系模式R的某个或某些关系满足的约束条件，而是指R的一切关系均要满足的约束条件。

（1分）3．错误（1分）非主属性是指不包含在任何候选码中的属性。

（1分）4．正确(1分)因为如果不存在非平凡的非函数的多值依赖，必为4NF，则也为BCNF，与假设矛盾。

（1分）5．错误（1分）两段封锁法仍有可能发生死锁，而且可能增多。

（1分）四、问答题（每小题10分，本大题共40分）1．设有两个关系R (A，B，C) 和S (C，D，E)，试用SQL查询语句表达下列关系代数表达式πA，E (σB = D (R∞S))。

答案要点：SELECT A，E --------3分FROM R，S --------3分WHERE B = D AND R.C = S.C --------4分2．设有关系模式R (A，B，C，D)，F是R上成立的FD集，F = {D→A，D→B}，试写出关系模式R的候选键，并说明理由。

答案要点：① R的候选键是CD --------4分②理由：从已知的F，可导出D→ABD，--------2分再根据增广律，可得出CD→ABCD， --------2分即CD值可决定全部属性值。

06级数据库试卷(双面)A

第2页共6页A. 外模式B. 逻辑模式C. 内模式D. 概念模式 11. 从数据流图构造E-R 图时，选择实体一般应先考虑数据流图中的（）。

A. 数据项B. 数据流C. 数据处理D. 数据存储 12. 以下（）不是当前常用的存取方法。

A. 索引方法B. 聚簇方法C. HASH 方法D. 链表方法 13. 事务一旦提交，对数据库的改变是永久的，这是事务的（）。

A. 原子性 B. 一致性 C. 隔离性 D. 持久性 14. 并发控制要解决的根本问题是保持数据库状态的（）。

A. 安全性 B. 完整性 C. 可靠性 D. 一致性 15. 在数据库系统中，对存取权限的定义称为（）。

A. 授权B. 定义C. 约束D. 审计16. 视图建立后，在数据字典中存放的是（）。

A. 查询语句 B. 视图的定义 C. 组成视图的表内容 D. 产生视图的表定义 17. 由全码组成的关系模式，最高可以达到的模式为（）。

A. 4NFB. 2NFC. 3NFD. BCNF18. 下列叙述中，正确的是（）。

A. 对于关系数据模型，规范化程度越高越好 B. 如果F 是最小函数依赖集，则R ∈2NF C. 如果R ∈BCNF ，则F 是最小函数依赖集D. 关系模式分解为BCNF 后，函数依赖关系可能被破坏19. 为保证多用户环境中数据的完整性和一致性，DBMS 采取的控制称为（）。

A. 安全性控制B. 完整性控制C. 事务控制D. 并发控制20. 包含在日志文件中的主要内容是（）。

A. 程序运行过程B. 对数据的全部操作C. 对数据的全部更新操作D. 程序执行结果二、填空题（每题1分，共10分）1. 关系模式R 与S ，组成关系R ÷S 的是关系（）的属性集。

2. 在SQL 中视图是由（）产生的虚表。

3. 在SQL 中X not between 20 and 30 的含义是（）。

《数据库应用》A卷(含答案)

华南农业大学期末考试答卷（A 卷）参考答案2017学年第一学期考试科目：数据库应用A 考试类型：（闭卷）考试时间： 120 分钟学号姓名年级专业班级① 本试题分为试卷与答卷两部分。

试卷有四大题，共9页。

不能使用计算器。

②③ ②⑤ 机读卡上请写姓名、班级、学号，学号只写后10位（例如：201531140701，只写1531140701）。

用签字笔填写这些信息时不要写在机读区域，以免影响机读的成绩。

一、判断题(共20小题，每小题0.5分，共10分。

在答题卡上涂黑A 代表正确，涂黑B 代表错误）二、单选题（共40小题，每小题1分，共40分。

涂黑答题卡上对应的项）三、填空题（共10小题、10个空，每空1分，共10分）四、应用题（共5题，共40分。

写清题号）1、某个旅游数据库系统有“团队”和“线路”两个表，如下所示。

应用关系运算完成下列题目。

（本题共5小题，每小题2分，共10分）答：（1）（2（3（4）∏线路ID ，线路名，费用(σ天数>6（线路）)（5）∏线路名，天数(σ导游姓名=‘王选’（团队线路）)2、下列前两个小题写出每条SQL 语句完成的功能，后三小题根据每种功能要求写出相应的SQL 语句。

（本题共5小题，每小题2分，共10分）答：(1) 查找商品名称为"蓝月亮洗衣液" 的供应信息，显示供应商编号，商品编号，商品类别，供应日期。

(2) 查找供应数量大于1000的供应商信息，显示供应商编号，供应商名称，联系电话，地址。

(3) SELECT商品名称，商品类别，单价，折扣FROM 供应明细，商品WHERE 商品. 商品编号=供应明细. 商品编号AND 数量between 1000 and 2000；(4) Select 商品类别, Max(单价) As最高单价From商品Group by 商品类别;(5) Delete From 商品Where 单价<30;3、教师管理数据库中有两个表，表的结构如下：教师（教师编号，姓名，性别，出生年月，籍贯，学院编号）；工资(教师编号，基本工资，绩效工资，津贴，住房公积金，养老保险，失业保险)。

2006年理数据库原理试卷A

B.Begin、Continue、End
C.Create Transaction、Commit、RollBack
D.Begin Transaction、Continue、End
14.以下哪种情况应尽量创建索引（）。
A.在Where子句中出现频率较高的列
B.具有很多NULL值的列
C.记录较少的基本表
D.需要更新频繁的基本表
A.∪，-，×，π和σB.∪，-，∞，π和σ
C.∪，∩，×，π和σD.∪，∩，∞，π和σ
5.当关系R和S自然联接时，能够把R和S原该舍弃的元组放到结果关系中的操作是（）
A.左外联接B.右外联接C.外部并D.外联接
6.下述哪一条不是由于关系模式设计不当而引起的？
A)数据冗余B)插入异常C)丢失修改D)更新异常
A)雇员号B)雇员名C)部门号D)工资
第（18）至（20）题基于以下的叙述：有关系模式A（C，T，H，R，S），基中各属性的含义是：C：课程T：教员H：上课时间R：教室S：学生
根据语义有如下函数依赖集：
F={C→T，（H，R）→C，（H，T）→R，（H，S）→R}
18.关系模式A的码是
A) CB)（H，R）C)（H，T）D)（H，S）
16.若执行下面列出的操作，哪个操作不能成功执行？（）
A)从DEPT中删除部门号=‘03’的行
B）在DEPT中插入行（‘06’，‘计划部’，‘6号楼’）
C)将DEPT中部门号=‘02’的部门号改为‘10’
D)将DEPT中部门号=‘01’的地址改为‘5号楼’
山东建筑大学试卷共2页第2页
17.在雇员信息表关系EMP中，哪个属性是外键（foreign key）？（）
第（15）至（17）题是基于如下两个关系，其中雇员信息表关系EMP的主键是雇员号，部门信息表关系DEPT的主键是部门号

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06级数据库A卷
东莞理工学院（本科）试卷（A 卷） 2008--2009学年第2学期《数据库系统原理II 》试卷开课单位：计算机学院，考试形式：闭卷
一、选择题（共30分每题2分） 1．数据库与文件系统的本质区别是（）。

A ．避免数据冗余 B ．数据结构化 C ．支持分布处理 D ．需要大容量磁盘 2．若事务T 对数据对象A 加上X 锁，则（） A. 只允许T 修改
A ，其它任何事务都不能再对A 加任何类型的锁 B. 只允许T 读取A ，其它任何事务都不能再对A 加任何类型的锁 C. 只允许T 读取和修改A ，其它任何事务都不能再对A 加任何类型的锁 D. 只允许T 修改A ，其它任何事务都不能再对A 加X 锁
3．以下哪个选项属于概念模型的表示方法？（）
A ．视图
B ．关系
C ．E-R 图
D ．SQL 语句
4．关系数据模型由（）、完整性约束规则和关系运算三部分构成。

A ．数据类型
B ．数据结构
C．数据组织 D．以上都不是
5．在需求分析阶段，数据字典是对系统中（）。

A．数据的描述 B、处理的描述
C．功能的描述 D、数据与处理关系的描述
6．选择某种索引方法是数据库设计过程中（）阶段的任务。

A．需求分析 B．概念设计
C．逻辑设计 D．物理设计
7．数据库的逻辑工作单位是（）。

A．命令 B．文件
C．指令 D．事务
8．关系模型的参照完整性规则要求关系中（）
A．不允许引用不存在的元组 B．允许引用不存在的元组
C．不允许引用不存在的属性 D．允许引用不存在的属性
9．在数据库系统中，当数据库的模式改变时，用户程序可以不做改变。

这是数据的（）
A．物理独立性 B．逻辑独立性
C．位置独立性 D．存储独立性
10．对两段锁协议的不正确描述是（）
A．两段锁协议把所有事务分为数据项加锁和解锁两个阶段
B．事务在释放阶段不能再申请任何锁
C．遵守两阶段锁协议是可串行化调度的充分条件
D ．事务遵守两阶段锁协议不会发生死锁
11．设关系R(A,B,C)，与SQL 语句SELECT DISTINCT A FROM R WHERE B=17等价的关系代数表达式是（）
A ．))((17R
B A =∏σ B ．)(17R B =σ
C ．))((,17R C A B ∏=σ
D ．))((17,R B C A =∏σ
12．下列SQL 语句中，哪一（些）组包含了不正确的定义语句（） I 、 CREATE TABLE … CREATE VIEW … CREATE INDEX …
II 、 DROP TABLE … DROP VIEW … DROP INDEX …
III 、 ALTER TABLE … ALTER VIEW … ALTER INDEX …
A ．只有I
B ．只有II
C ．只有III
D ．I 和II
13．下面对索引的相关描述正确的是：（）。

A ．经常被查询的列不适合建索引
B ．列值唯一的列适合建索引
C ．有很多重复值的列适合建索引
D ．是外键或主键的列不适合建索引
14．下列说法中正确的是（）
A ．SQL 中局部变量可以不声明就使用
B ．SQL 中全局变量必须先声明再使用
C ．SQL 中所有变量都必须先声明后使用
D ．SQL 中只有局部变量先声明后使用；全局变量是由系统提供的用户不能自己建立。

15．下列说法正确的是（）。

A ．视图是观察数据的一种方法，只能基于基本表建立
B ．视图是虚表，观察到的数据是实际基本表中的数据
C ．索引查找法一定比表扫描法查询速度快
D ．索引的创建只和数据的存储有关系二、填空题（共10分每题1分） 16．外模式/模式映象为数据库提供了___________独立性。

17．关系操作的特点是操作。

18．SQL 的中文含义是。

19．一个事务成功完成后，它对数据库的改变必须是永久的。

这一特性称为事务的。

20．1NF ，2NF ，和3NF 之间，相互是一种关系。

21．介质故障的恢复需要。

22．关系数据库规范化理论的研究中，在函数依赖的范围内，达到了最高的规范化程度。

23．DBMS 对数据库进行封锁时采用的两种基本的锁类型，即排它锁和。

24．是防止数据库中的数据在存储和传输中失密的有效手段。

25．数据库中，每个事务都感觉不到系统中其他事务在并发地执行，这一特性称为事务的____________。

三、简答题（共10分，每题5分）
26．试述数据模型的概念、数据模型的作用和数据模型的三要素。

27．请简述数据库应用设计分为哪几个阶段，每个阶段的任务、内容。

四、应用题（共50分）
28．设有关系模式Ｒ(U，F)，其中U={A,B,C,D,E},Ｆ＝｛A → BC, C→ D,BC→ E,E →A｝，则判断分解：ρ＝｛R1(ABCE),R2(CD)｝是否具有无损连接性，是否保持函数依赖。

要求给出证明过程。

（10分）
29．设有一个SPJ数据库，包括S、P、J、SPJ4个关系模式：
S（SNO,SNAME,STATUS,CITY）;
P（PNO,PNAME,COLOR,WEIGHT）;
J（JNO,JNAME,CITY）;
SPJ（SNO,PNO,JNO,QTY）;
供应商表S由供应商代码（SNO）、供应商姓名（SNAME）、供应商状态（STATUS）、供应商所在城市（CITY）组成；
零件表P由零件代码(PNO)、零件名（PNAME）、颜色（COLOR）、重量（WEIGHT）组成；
工程项目表J由工程项目代码（JNO）、工程项目名（JNAME）、工程项目所在城市（CITY）组成；
供应情况表SPJ由供应商代码（SNO）、零件代码（PNO）、工程项目代码（JNO）、供应数量QTY组成，表示某供应商供应某种零件给某工程项目的数量为QTY。

使用关系代数完成如下查询：
（1）求供应工程 J1零件的供应商号码SNO；（3分）
（2）求供应工程J1零件P1的供应商号码SNO；（3分）
（3）求供应工程J1零件为红色的供应商号码SNO；（3分）
（4）求没有使用天津供应商生产的红色零件的工程号JNO；（3分）
（5）求至少用了供应商S1所供应的全部零件的工程号JNO。

（3分）
30．设有一教学数据库，包括S、C、SC3个关系模式：
S（SNO,SNAME,SAGE,SEX）;
C（CNO,CNAME,GRADE,DEPARTMENT）;
SC（SNO,CNO,SCORE）;
学生表S由学号（SNO）、姓名（SNAME）、年龄（SAGE）、性别（SEX）组成；
课程表P由课程代码(CNO)、课程名（CNAME）、学分（GRADE）、开课院系（DEPARTMENT）组成；
选课表由学号（SNO）、课程号（CNO）、成绩（SCORE）组成，表示某学生选修某课程的成绩为SCORE。

使用SQL语句完成如下功能：
（1）创建视图sv，在该视图中显示学生的学号，姓名，平均成绩；（5分）
（2）查询选修了数据库课程的学生人数；（5分）
（3）查询选修人数超过10人的课程的代码。

（5分）
精品资料
31．假设某公司的业务规则如下：
（1）公司下设几个部门，如技术部、财务部、市场部等。

（2）每个部门承担多个工程项目，每个工程项目属于一个部门。

（3）每个部门有多名职工，每一名职工只能属于一个部门。

（4）一个职工可能参与多个工程项目，且每个工程项目有多名职工参与施工。

根据职工在工程项目中完成的情况发放酬金。

（5）工程项目有工程号、工程名两个属性；部门有部门号、部门名称两个属性；职工有职工号、姓名、性别属性；
问题：
1.根据上述规则设计E-R模型(5分)
2.将E-R模型转换成关系模式，并指出主键和外键 (5分)
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