红孩子“垂直网站集合体”能否挑战“大一统” 模式

合集下载

主流B2C网站京东商城、红孩子、凡客诚品、当当网的营销模式探讨

主流B2C网站京东商城、红孩子、凡客诚品、当当网的营销模式探讨第一篇：主流B2C网站京东商城、红孩子、凡客诚品、当当网的营销模式探讨众所周知，从美国的AMAZON到国内的卓越、当当、红孩子、京东，红孩子，几乎所有的著名B2C都是依靠低价策略起家，通过与传统行业同行或线上竞争对手的价格战获得市场份额。

低价策略可以帮助企业进入市场，但是想在市场中真正立足，最重要的还是要在网络营销工作上下功夫。

红孩子：以低价进入市场，以提供便利的消费方式赢得用户红孩子在2004年进入母婴产品销售行业之前，该领域已有两家成熟的零售企业，一家是以实体店铺销售为主的丽家宝贝，一家是以网络销售为主的乐友，红孩子面对已经在业内站稳脚跟的前辈，采用的方式是低价策略和自己独有的“目录销售+电子商务”联合销售模式。

红孩子的低价策略给行业造成了很大的冲击，在红孩子创立之前，业内利润率在25%以上，红孩子直接将利润率限定在15%。

当然，对于杀入市场的红孩子而言，其武器不仅仅是低价。

如今许多同行纷纷开设实体店，红孩子认为，对于顾客来说，有店面与无店面并不是最重要的，重要的是能否给他们带来消费的便利。

与很多B2C网站采用第三方物流相比，自办物流恰好是红孩子的杀手锏。

据了解，红孩子在全国已有 17个分公司，每个分公司都有自己的物流团队，并设有自己的中心仓库和配送站点。

或许正是由于自办物流的优势，红孩子“一条家庭购物高速公路”的理念才得以落地。

母婴用品市场对红孩子来说只不过是一个开始。

红孩子的目标是家庭购物市场。

在红孩子的经营思路中，对一个年轻的母亲来说，她的家庭采购任务已经不仅仅是婴童产品，还包括化妆品、家居用品、健康产品，甚至还有消费电子产品等，这些都是列在每一个家庭的日常采购计划之中的，从母婴到百货，按照用户的购买需求去发展销售品类是红孩子立足母婴用品销售市场后，继续扩张的主要策略，红孩子其实做的是对B2C的进一步细分，即B2F（business to family）。

红孩子网站应用分析

网站系统结构分析
二、首页分析 1、首页一级目录主要由红孩子母婴网、站、缤购网上商城和社区构成体现公司的以母婴产品为主的、体现公司的以母婴产品为主的、向“大而全” 而全”的多样化商品一站式购物平台转变的多元化战略同时也是社会化营销的手段，同时也是社会化营销的手段，而且两个商城，一个账号，一个购物车，商城，一个账号，一个购物车，也为用户提供了方便。户提供了方便。 2、首页处促销广告牌和目录订阅、首页23处促销广告牌和目录订阅体现站内营销和特色目录营销
网站系统结构分析
>用户条款及隐私权政策用户条款及隐私权政策 1、红孩子网站上说明了关于账户、产品、红孩子网站上说明了关于账户、说明、价格变化和缺货、送货、评论、说明、价格变化和缺货、送货、评论、意见、消息、条款修正、意见、消息、条款修正、争议等的相关事宜及解决方案，事宜及解决方案，让用户进一步建立信任。 /fwtk.html ，/yssm.html
红孩子购物网站应用分析
历时14天吐血打造历红孩子的表现走进红孩子我看红孩子
价排名广告商数量、 · 谷歌搜索第一页个推广链接谷歌搜索第一页11个推广链接
网站系统结构分析
三、争取用户信任感分析优点：优点： >建立网站专业化形象建立网站专业化形象 1、首页的育婴指南提供了7个育婴阶段的、首页的育婴指南提供了个育婴阶段的指导，包括妈妈的身体变化，指导，包括妈妈的身体变化，宝宝的生长状况，其间的营养与饮食指导、长状况，其间的营养与饮食指导、现阶段的妈妈都在用什么？、胎教推荐、？、胎教推荐段的妈妈都在用什么？、胎教推荐、孕妈妈心理建议和生活保健建议及相关产品推荐、爸爸应该做的事儿（品推荐、爸爸应该做的事儿（指向社区） /cuxiao/4148 0.html

2952020-ISTQB-sample-question-paperspart-1

ISTQB CertificationSample Question PapersCopyright © Abhishek Kumar TiwariAll rights reserved. No part of this material may be reproduced or transmitted in any form or by any means, electronic or mechanical, including photocopying, recording, or by any information storage and retrieval system, without prior permission from the owner. Contact the owner for the information on foreign rights.Question Paper 1:1.An input field takes the year of birth between 1900 and 2004The boundary values for testing this field area.0,1900,2004,2005b.1900, 2004c.1899,1900,2004,2005d.1899, 1900, 1901,2003,2004,20052.Which one of the following are non-functional testing methods?a.System testingability testingc.Performance testingd.Both b & c3.Which of the following tools would be involved in the automation of regressiontest?a.Data testerb.Boundary testerc.Capture/Playbackd.Output comparator.4.Incorrect form of Logic coverage is:a.Statement Coverageb.Pole Coveragec.Condition Coveraged.Path Coverage5.Which of the following is not a quality characteristic listed in ISO 9126 Standard?a.Functionalityabilityc.Supportabilityd.Maintainability6.To test a function, the programmer has to write a _________, which calls thefunction to be tested and passes it test data.a.Stubb.Driverc.Proxyd.None of the above7.Boundary value testinga.Is the same as equivalence partitioning testsb.Test boundary conditions on, below and above the edges of input andoutput equivalence classesc.Tests combinations of input circumstancesd.Is used in white box testing strategy8.Pick the best definition of qualitya.Quality is job oneb.Zero defectsc.Conformance to requirementsd.Work as designed9.Fault Masking isa.Error condition hiding another error conditionb.Creating a test case which does not reveal a faultc.Masking a fault by developerd.Masking a fault by a tester10.One Key reason why developers have difficulty testing their own work is :ck of technical documentationck of test tools on the market for developersck of trainingck of Objectivity11.During the software development process, at what point can the test process start?a.When the code is complete.b.When the design is complete.c.When the software requirements have been approved.d.When the first code module is ready for unit testing12.In a review meeting a moderator is a person whoa.Takes minutes of the meetingb.Mediates between peoplec.Takes telephone callsd.Writes the documents to be reviewed13.Given the Following programIF X < YTHEN Statement 1;ELSE IF Y >= ZTHEN Statement 2;ENDMcCabe’s Cyclomatic Complexity is :a. 2b. 3c. 4d. 514.How many test cases are necessary to cover all the possible sequences ofstatements (paths) for the following program fragment? Assume that the twoconditions are independent of each other : -…………if (Condition 1)then statement 1else statement 2fiif (Condition 2)then statement 3fi…………a.Test Casesb. 3 Test Casesc. 4 Test Casesd.Not achievable15. Acceptance test cases are based on what?a.Requirementsb.Designc.Coded.Decision table16. “How much testing is enough?”a.This question is impossible to answerb.This question is easy to answerc.The answer depends on the risk for your industry, contract and specialrequirementsd.This answer depends on the maturity of your developers17. A common test technique during component test isa.Statement and branch testingability testingc.Security testingd.Performance testing18.Statement Coverage will not check for the following.a.Missing Statementsb.Unused Branchesc.Dead Coded.Unused Statement19.Independent Verification & Validation isa.Done by the Developerb.Done by the Test Engineersc.Done By Managementd.Done by an Entity Outside the Project’s sphere of influence20.Code Coverage is used as a measure of what ?a.Defectsb.Trends analysisc.Test Effectivenessd.Time Spent TestingQuestion Paper 2:Q2Regression testing should be performed:v) every week w) after the software has changed x) as often as possible y) when the environment has changed z) when the project manager says NOTE: Only one answer per question Q1A deviation from the specified or expected behaviour that is visible to end-users is called:a) an error b) a faulta) v & w are true, x, y & z are false b) w, x & y are true, v & z are false c) w & y are true, v, x & z are false d) w is true, v, x, y & z are falseQ3IEEE 829 test plan documentation standard contains all of the following except c) a failure d) a defecta) test items b) test deliverables c) test tasks d) test specificationsQ4When should testing be stopped?a) when all the planned tests have been run b) when time has run outc) when all faults have been fixed correctlyd) it depends on the risks for the system being testedQ5Order numbers on a stock control system can range between 10000 and 99999 inclusive. Which of the following inputs might be a result of designing tests for only valid equivalence classes and valid boundaries?a) 1000, 50000, 99999 b) 9999, 50000, 100000 c) 10000, 50000, 99999 d) 10000, 99999, 100000Q6 Consider the following statements about early test design:i. early test design can prevent fault multiplicationii. faults found during early test design are more expensive to fixiii. early test design can find faultsiv. early test design can cause changes to the requirementsv. early test design normally takes more efforta) i, iii & iv are true; ii & v are falseb) iii & iv are true; i, ii & v are falsec) i, iii, iv & v are true; ii is falsed) i & ii are true; iii, iv & v are falseQ7 Non-functional system testing includes:a) testing to see where the system does not function correctlyb) testing quality attributes of the system including performance and usabilityc) testing a system function using only the software required for that functiond) testing for functions that should not existQ8 Which of the following is NOT part of configuration management?a) auditing conformance to ISO 9000b) status accounting of configuration itemsc) identification of test versionsd) controlled library accessQ9Which of the following is the main purpose of the integration strategy for integration testing in the small?a) to ensure that all of the small modules are tested adequatelyb) to ensure that the system interfaces to other systems and networksc) to specify which modules to combine when, and how many at onced) to specify how the software should be divided into modulesQ10 What is the purpose of a test completion criterion?a) to know when a specific test has finished its executionb) to ensure that the test case specification is completec) to set the criteria used in generating test inputsd) to determine when to stop testingQ11 Consider the following statements:i. an incident may be closed without being fixed.ii. incidents may not be raised against documentation.iii. the final stage of incident tracking is fixing.iv. the incident record does not include information on test environments.a) ii is true, i, iii and iv are falseb) i is true, ii, iii and iv are falsec) i and iv are true, ii and iii are falsed) i and ii are true, iii and iv are falseQ12 Given the following code, which statement is true about the minimum number of test cases required for full statement and branch coverage?Read pRead qIF p+q > 100 THENPrint"Large"ENDIFIF p > 50 THENPrint "p Large"ENDIFa) 1 test for statement coverage, 3 for branch coverageb) 1 test for statement coverage, 2 for branch coveragec) 1 test for statement coverage, 1 for branch coveraged) 2 tests for statement coverage, 2 for branch coverageQ13 Consider the following statements:i. 100% statement coverage guarantees 100% branch coverage.ii. 100% branch coverage guarantees 100% statement coverage.iii. 100% branch coverage guarantees 100% decision coverage.iv. 100% decision coverage guarantees 100% branch coverage.v. 100% statement coverage guarantees 100% decision coverage.a) ii is True; i, iii, iv & v are Falseb) i & v are True; ii, iii & iv are Falsec) ii & iii are True; i, iv & v are Falsed) ii, iii & iv are True; i & v are FalseQ14 Functional system testing is:a) testing that the system functions with other systemsb) testing that the components that comprise the system function togetherc) testing the end to end functionality of the system as a wholed) testing the system performs functions within specified response timesQ15 Incidents would not be raised against:a) requirementsb) documentationc) test casesd) improvements suggested by usersQ16 Which of the following items would not come under Configuration Management?a) operating systemsb) test documentationc) live datad) user requirement documentsQ17 Maintenance testing is:a) updating tests when the software has changedb) testing a released system that has been changedc) testing by users to ensure that the system meets a business needd) testing to maintain business advantageQ18 What can static analysis NOT find?a) the use of a variable before it has been definedb) unreachable (“dead”) codec) memory leaksd) array bound violationsQ19 Which of the following techniques is NOT a black box technique?a) state transition testingb) LCSAJc) syntax testingd) boundary value analysisQ20 Beta testing is:a) performed by customers at their own siteb) performed by customers at the software developer's sitec) performed by an Independent Test Teamd) performed as early as possible in the lifecycleQ21 Given the following types of tool, which tools would typically be used by developers, and which by an independent system test team?analysisi. statictestingii. performancemanagementiii. testanalysisiv. dynamica) developers would typically use i and iv; test team ii and iiib) developers would typically use i and iii; test team ii and ivc) developers would typically use ii and iv; test team i and iiid) developers would typically use i, iii and iv; test team iiQ22 The main focus of acceptance testing is:a) finding faults in the systemb) ensuring that the system is acceptable to all usersc) testing the system with other systemsd) testing from a business perspectiveQ23 Which of the following statements about component testing is FALSE?a) black box test design techniques all have an associated test measurement techniqueb) white box test design techniques all have an associated test measurement techniquec) cyclomatic complexity is not a test measurement techniqued) black box test measurement techniques all have an associated test design techniqueQ24 Which of the following statements is NOT true?a) inspection is the most formal review processb) inspections should be led by a trained leaderc) managers can perform inspections on management documentsd) inspection is appropriate even when there are no written documentsQ25 A typical commercial test execution tool would be able to perform all of the following, EXCEPT:a) calculating expected outputsb) comparison of expected outcomes with actual outcomesc) recording test inputsd) reading test values from a data fileQ26 The difference between re-testing and regression testing is:a) re-testing ensures the original fault has been removed; regression testing looks forunexpected side-effectsb) re-testing looks for unexpected side-effects; regression testing ensures the original fault hasbeen removedc) re-testing is done after faults are fixed; regression testing is done earlierd) re-testing is done by developers; regression testing is done by independent testersQ27 Expected results are:a) only important in system testingb) only used in component testingc) most useful when specified in advanced) derived from the codeQ28 What type of review requires formal entry and exit criteria, including metrics:a) walkthroughb) inspectionc) management reviewd) post project reviewQ29 Which of the following uses Impact Analysis most?a) component testingb) non-functional system testingc) user acceptance testingd) maintenance testingQ30 What is NOT included in typical costs for an inspection process?a) setting up forms and databasesb) analysing metrics and improving processesc) writing the documents to be inspectedd) time spent on the document outside the meetingQ31 Which of the following is NOT a reasonable test objective:a) to find faults in the softwareb) to prove that the software has no faultsc) to give confidence in the softwared) to find performance problemsQ32 Which expression best matches the following characteristics of the review processes:1. led by the author2. undocumented3. no management participation4. led by a moderator or leader5. uses entry and exit criterias) inspectiont) peer reviewu) informal reviewv) walkthrougha) s = 4 and 5, t = 3, u = 2, v = 1b) s = 4, t = 3, u = 2 and 5, v = 1c) s = 1 and 5, t = 3, u = 2, v = 4d) s = 4 and 5, t = 1, u= 2, v = 3Q33 Which of the following is NOT part of system testing?a) business process-based testingb) performance, load and stress testingc) usability testingd) top-down integration testingQ34 Which statement about expected outcomes is FALSE?a) expected outcomes are defined by the software's behaviourb) expected outcomes are derived from a specification, not from the codec) expected outcomes should be predicted before a test is rund) expected outcomes may include timing constraints such as response timesQ35 The standard that gives definitions of testing terms is:a) ISO/IEC 12207b) BS 7925-1c) ANSI/IEEE 829d) ANSI/IEEE 729Q36 The cost of fixing a fault:a) is not importantb) increases the later a fault is foundc) decreases the later a fault is foundd) can never be determinedQ37 Which of the following is NOT included in the Test Plan document of the Test Documentation Standard?a) what is not to be testedb) test environment propertiesc) quality plansd) schedules and deadlinesQ38 Could reviews or inspections be considered part of testing?a) no, because they apply to development documentationb) no, because they are normally applied before testingc) yes, because both help detect faults and improve qualityd) yes, because testing includes all non-constructive activitiesQ39 Which of the following is not part of performance testing?a) measuring response timesb) recovery testingc) simulating many usersd) generating many transactionsQ40 Error guessing is best used:a) after more formal techniques have been appliedb) as the first approach to deriving test casesc) by inexperienced testersd) after the system has gone liveQuestion Paper 3:1. What is failure?A. Deviation from expected result to actual resultB. Defect in the software.C. Error in the program code.D. Fault in the system.2. People who don’t participate in technical reviewsA. AnalystsB. ManagementC. DevelopersD. Testers3. What type of testing is done to supplement the rigorous testing?A. Regression testing.B. Integration testing.C. Error GuessingD. System testing.4. Capture and replay facilities are least likely to be used to ….A. Performance testingB. Recovery testingC. GUI testingD. User requirements.5. What is the smallest number of test cases required toProvide 100% branch coverage?If(x>y) x=x+1; else y=y+1;while(x>y){y=x*y; x=x+1;}A. 1B. 2C. 3D. 46. Cyclomatic complexity is used to calculateA. number of independent paths in the basis set of a programB. number of binary decisions + 1C. upper bound for the number of tests that must be conducted to ensure that all statements have been executed at least onceD. number of branches and decisions7. If a candidate is given an exam of 40 questions, should get 25 marks to pass (61%) and should get 80% for distinction, what is equivalence class.A. 23, 24, 25B. 0, 12, 25C. 30, 36, 39D. 32,37,408. Match the following:1. Test estimation2. Test control3. Test monitoringa. measures of tracking processb. effort required to perform activitiesc. reallocation of resourcesA. 1-b, 2-c, 3-aB. 1-b, 2-a, 3-cC. 1-c, 2-a, 3-bD. 1-a, 2-b, 3-c9. One of the following is not a part of white box testing asper BS7925-II standards.A. Random testingB. Data Flow testing.C. Statement testing.D. Syntax testing.10. Exclusive use of white box testing in a test-phase will:A. Ensure the test item is adequately tested.B. Make the need for black-box testing redundant.C. Run the risk that the requirements are not satisfied.D. Suffices for the unit testing phase.11. Match the following.1. Configuration identification2. Configuration control3. Status reporting4. Configuration auditinga. Maintains of CI’s in a libraryb. Checks on the contents of the libraryc. Function recording and tracking problems.d. Requires the all CI’s and their versions in the systemare knownA. 1-d, 2-c, 3-d, 4-a.B. 1-d, 2-a, 3-c, 4-b.C. 1-a, 2-b, 3-d, 4-c.D. 1-c, 2-b, 3-a, 4-d.12. Cost of the reviews will not include.A. Review process itselfB. Metrics analysisC. Tool support.D. Process improvement.13. What type of testing will you perform on internet banking solution?A. System integrationB. Functional testingC. Non-functional testing.D. Requirements testing14. Which tool will be used to test the flag memory leaks and unassigned pointersA. Dynamic analysis toolB. Static Analysis tool.C. Maintenance tool.D. Configuration tool.15. Which of the following is not included in Test Plan.A. Features to be tested.B. Environmental needs.C. Suspension criteria.D. Expected results.16. A piece of software has been given….what tests in the Following will you perform?1) Test the areas most critical to business processes2) Test the areas where faults will be maximum3) Test the easiest functionalitiesA. 1&2 are true and 3 is false.B. 1,2&3 are true.C. 1 is true, 2&3 are false.D. 1&2 are false, 3 is true.17. Amount of testing performed will not depend onA. Risks involvedB. Contractual requirementsC. Legal requirementsD. Test data.18. Which of the following provides the biggest potential cost saving from use of CAST?A. Test managementB. Test designC. Test planningD. Test execution19. Testing is not done to ….A. Find faultsB. Improve qualityC. Check user friendliness.D. Improve software accuracy20. Software quality is not relevant to …A. CorrectnessB. UsabilityC. ViabilityD. Reusability.21. Which of the following are false?A. Incidents should always be investigated and resolved.B. Incidents occur when expected and actual results differ.C. Incidents can be analyzed to assist in test process improvement.D. An incident can be raised against documentation.22. Which of the following is a type of non-functional testing?A. Usability testing.B. Statement Coverage.C. Dataflow testing.D. Cause-effect graphing.23. To make a test effective it is most important that:A. It is easy to execute.B. It is designed to detect faults if present.C. The expected outcome is specified before execution.D. It is unlikely to delay progress.24. Error guessing is:A. An appropriate way of deriving system tests.B. Only used if good requirements are not available.C. Only used when good requirements are available.D. The most appropriate way of deriving system tests.25. A standard for software testing terminology is:A. IEEE 802.11B. ISO 9001C. BS 7925-1D. BS 7925-226. Which of the following is true of V-model?A. It includes the verification of designs.B. It states that modules are tested against user requirements.C. It specifies the test techniques to be used.D. It only models the testing phase.27. Which of the following is NOT part of a high level test plan?A. Functions not to be tested.B. Environmental requirements.C. Analysis of Specifications.D. Entry and Exit criteria.28. When do you stop testing?A. When the specified number of faults are found.B. When the test completion criteria are met.C. When all high and medium priority tests are complete.D. When all statements have been executed.29. Which of the following is least important in test management?A. Estimating test duration.B. Incident Management.C. Configuration Management.D. De-bugging.30. How would you estimate the amount of re-testing likely to be required?A. Metrics from previous similar projects.B. Discussions with the development team.C. Time allocated for regression testing.D. Both A & B.31. Which of the following statements is true of static analysis:A. Compiling code is not a form of static analysis.B. Static analysis need not be performed before imperative code is executed.C. Static analysis can find faults that are hard to find withdynamic testing.D. Extensive statistic analysis will not be needed if white-Box testing is to be performed.32. Regression testing always involvesA. Testing whether a known software fault been fixed.B. Executing a large number of different tests.C. Testing whether modifications have introduced adverseside effects.D. Using a test automation tool.33. A field failure occurs when multiple users access a system.Which of the following is true?A. This is an acceptable risk of a multi-user system.B. Insufficient functional testing has been performed.C. This indicates an important non-functional requirement was not specified and tested.D. It is not possible to test against such events prior to release.34. Integration testing in the large involves:A. Testing the system when combined with other systems.B. Testing a sub-system using stubs and drivers.C. Testing a system with a large number of users.D. Combing software components and testing them in onego.35. Data flow analysis studies:A. How rapidly data is transferred through a program.B. The rate of change of data values as a program executes.C. The use of data on paths through the code.D. The intrinsic complexity of the code.36. The oracle assumption is that:A. There is some existing system against which test outputmay be checked.B. The tester knows everything about the software undertest.C. The tester can routinely identify the correct outcome ofa test.D. Tools are used to check the results of testing.36 The following text will be used in Q.37 and Q.38. In a system designed to work out the tax to be paid:An employee has $4000 of salary tax freeThe next $1500 is taxed at 10%The next $28000 is taxed at 22%Any further amount is taxed at 40%37. To the nearest $ which of these is a valid Boundary Value Analysis test case?A. $1500B. $32001C. $28000D. $3350138. Which of these groups of numbers would fall into the same equivalence class?A. $5800; $28000; $32000B. $0; $200; $4200C. $5200; $5500; $28000D. $28001; $32000; $3500039. Which of the following is NOT a characteristic of User Acceptance Testing?A. Use of automated test execution tools.B. Testing performed by users.C. Testing against acceptance test criteria.D. Integration of system with user documentation.40. For software to be reliable it must:A. Be easy to maintain.B. Be unlikely to cause a failure.C. Never fail under any circumstances.D. Be written according to coding standardsQuestion Paper 4:1 We split testing into distinct stages primarily because:a) Each test stage has a different purpose.b) It is easier to manage testing in stages.c) We can run different tests in different environments.d) The more stages we have, the better the testing.2 Which of the following is likely to benefit most from the use of test tools providing test capture and replay facilities?a) Regression testingb) Integration testingc) System testingd) User acceptance testing3 Which of the following statements is NOT correct?a) A minimal test set that achieves 100% LCSAJ coverage will also achieve 100% branch coverage.b) A minimal test set that achieves 100% path coverage will also achieve 100% statement coverage.c) A minimal test set that achieves 100% path coverage will generally detect more faults than one that achieves 100% statement coverage.d) A minimal test set that achieves 100% statement coverage will generally detect more faults than one that achieves 100% branch coverage.4 Which of the following requirements is testable?a) The system shall be user friendly.b) The safety-critical parts of the system shall contain 0 faults.c) The response time shall be less than one second for the specified design load.d) The system shall be built to be portable.5 Analyse the following highly simplified procedure:Ask: “What type of ticket do you require, single or return?”IF the customer wants ‘return’Ask: “What rate, Standard or Cheap-day?”IF the customer replies ‘Cheap-day’Say: “That will be £11:20”ELSESay: “That will be £19:50”ENDIFELSESay: “That will be £9:75”ENDIFNow decide the minimum number of tests that are needed to ensure that allthe questions have been asked, all combinations have occurred and allreplies given.a) 3b) 4c) 5d) 66 Error guessing:a) supplements formal test design techniques.b) can only be used in component, integration and system testing.c) is only performed in user acceptance testing.d) is not repeatable and should not be used.7 Which of the following is NOT true of test coverage criteria?a) Test coverage criteria can be measured in terms of items exercised by a test suite.b) A measure of test coverage criteria is the percentage of user requirements covered.c) A measure of test coverage criteria is the percentage of faults found.d) Test coverage criteria are often used when specifying test completion criteria.8 In prioritising what to test, the most important objective is to:a) find as many faults as possible.b) test high risk areas.c) obtain good test coverage.d) test whatever is easiest to test.9 Given the following sets of test management terms (v-z), and activity descriptions (1-5), which one of the following best pairs the two sets?v – test controlw – test monitoringx - test estimationy - incident managementz - configuration control1 - calculation of required test resources2 - maintenance of record of test results3 - re-allocation of resources when tests overrun4 - report on deviation from test plan5 - tracking of anomalous test resultsa) v-3,w-2,x-1,y-5,z-4b) v-2,w-5,x-1,y-4,z-3c) v-3,w-4,x-1,y-5,z-2d) v-2,w-1,x-4,y-3,z-510 Which one of the following statements about system testing is NOT true?a) System tests are often performed by independent teams.b) Functional testing is used more than structural testing.c) Faults found during system tests can be very expensive to fix.d) End-users should be involved in system tests.11 Which of the following is false?。

网课智慧树知道《“人人爱上H5”—数字广告设计(青岛黄海学院)》章节测试答案

第一章单元测试1【判断题】传统广告需要顺应时代进行转型，因此平面广告不再重要。

（）A.对B.错2【判断题】超媒体实现的条件包含、网络速度、超文本语言、设备支持、超媒体思维、用户使用需求五方面。

A.对B.错3【单选题】(2分)从HTML4.0、XHTML到HTML5，HTML5增加了很多非常实用的新功能和新特性，其中最具有代表性的优势是：A.跨平台B.效果丰富C.高级代码D.规范化4【单选题】(2分)“一镜到底”是一个___上常用的概念。

（）A.影视B.交互C.绘画D.游戏5.【多选题】(3分)正确答案：ABC超媒体的“非线性”把原本在一个时间点上只能呈现单一感觉的体验扩大到了听觉、视觉、交互维度，从而让人产生更为身临其境的代入感。

（）A.视觉B.交互C.听觉D.感官6.【多选题】(3分)正确答案：ABCD超媒体实现的条件包括：（）A.超文本语言B.超媒体思维C.设备支持D.网络速度第二章单元测试1【判断题】互联网设计派H5的缺点是技术普遍比较薄弱，传播性有限。

（）A.错B.对2【判断题】PV（Page View）通常指网站页面的浏览量／点击量，用户每1次对网站中的单个网页访问均被记录为1次，用户对同一页面的多次访问，访问量会被累计。

（）A.对B.错3【单选题】(2分)____和____是栏目包装设计行业的黄金搭档。

（）A.PS和AEB.AE和C4DC.C4D和3D MAXSD.PS和Maya4【单选题】(2分)根据ivx平台技术指引，建议设计尺寸为：（）A.750*1334B.640*1040C.960*640D.1136*6405.【多选题】(3分)正确答案：ABCD常用的网站类H5生成工具有：（）A.意派360、木疙瘩B.互动大师（iH5）、IvxC.易企秀、兔展D.MAKA、初页6.【多选题】(3分)正确答案：AB常用的声画编辑辅助工具有：（）A.Final cutB.Garage BandC.AxureD.Sketch第三章单元测试1【判断题】。

《电子商务案例分析》期末复习试题2套含答案

_____学年第___学期期末考试【A】卷【】卷《》试卷适用班级:（考试时间：100分钟）一、名词解释题（准确回答定义，每小题4分，共20分）1、电子商务案例2、B2B电子商务3、数字证书4、信息网络传播权5、目录营销二、填空题（每空1分，共10分）1、电子商务案例可分为已解决问题案例、__________ _ 和。

2、阿里巴巴网站是_______型电子商务网站，易趣网站是_______型电子商务网站。

3、按商品种类可将B2C电子商务分为和两种。

4、网络商务信息收集的要求：、、适度、经济。

5、搜索引擎营销方法主要有三种：、和使用自动搜索匹配技术的网站联盟广告的投放。

三、单项选择题（从下列各题的4个备选答案中选出一个正确答案，并将其序号填写在题干后面的括号内。

答案选错或未做选择，该题无分。

每题2分，共10分）1、（）B2B电子商务可以使产品和服务更接近消费者，可以稳定市场，提供信誉担保，搜索更经济，匹配买卖双方。

A综合类 B行业垂直类C专门类 D垂直类2、（）提供个人交易中介服务的免费交易服务，现正拓展B2C模式交易中介服务。

A 卓越 B淘宝C 京东商城D 国美3、世界上第一个目录诞生于15世纪的（），是一个关于书籍的目录。

A美国 B欧洲C中国 D非洲4、（）是也称为移动支付（Mobile Payment），简而言之，就是允许移动用户使用其移动终端（通常是手机）对所消费的商品或服务进行账务支付的一种服务方式。

A 手机支付 B网上支付C 网络银行D 第三方支付5、（）是一个机遇用户关系的信息分享、传播以及获取的平台，每一个听众（粉丝）都是潜在营销对象，允许用户通过WEB、WAP、Mail、App、IM、SMS以及各种客户端，以简短的文本进行更新和发布消息A 微信营销 B微博营销C网络营销 D无线营销四、判断题（下列命题你认为正确的就在题后括号内画“√”，错误的画“×”，并在题下空白处改正。

电商大战观察：不垂直的电商不是好电商

电商大战观察：不垂直的电商不是好电商垂直电商是指在某一个行业或细分市场深化运营的电子商务模式。

垂直电子商务网站旗下商品都是同一类型的产品，这种垂直化运营在国外早就有比较成熟的发展。

比如，美国最大的购物网站亚马逊虽然经营的产品包罗万象，但是各个产品类目都有自己的专业团队独立运营以符合不同用户的需求。

而在中国，红孩子是最为典型的垂直电商。

红孩子于2004年6月成立，目前已经是中国最大的母婴、化妆、食品、生活品类B2C网站。

红孩子在线销售的商品以母婴、化妆、食品、家居、保健、厨电等品类为主。

2012年9月25日，苏宁电器正式宣布以6600万美金收购红孩子，红孩子将作为苏宁易购母婴频道存在，在苏宁易购点击母婴频道后，直接跳转至红孩子网站，而红孩子以这一种方式独立存在。

红孩子可谓是垂直类电商中的典范，它的优势在于专注和专业。

红孩子通过精准的差异化定位能够提供更加符合母婴的消费产品，满足母婴用户的特定习惯;因此能够更容易取得用户信任，从而加深产品的印象和口碑传播，更是形成了品牌和独特的品牌价值。

红孩子究竟是怎样成功的，我们可以一探究竟，这样的探索也许能给创业者们一个学习的榜样。

100%正品，树立行业典范随着居民生活水平提高，婴幼儿产品已经成为刚性需求产品，消费者无不希望能够购买到安全、放心的母婴产品。

对母婴产品而言，消费者更为关注其信誉和质量保障。

在国内，母婴产品质量参差不齐、价格高高在上等问题让人诟病已久。

近年来众多母婴产品的安全问题越来越得到了公众的重视。

而红孩子作为专业的母婴类垂直电商，比之于别的平台电商在母婴用品服务上更专业，保证所有的母婴、美妆用品100%正品，不存在假货、水货。

红孩子也在不断加强与雅培等国际知名品牌之间的合作，红孩子母婴网选择与二、三十家国际知名奶粉品牌和国际奶粉消费商合作。

直供、专供、分销、效期检验、奶源地采访、无机奶粉引入……不断在努力延长销售的两头环节，为消费者把住第一道关卡。

中央广播电视大学中等专业成人学历招生电子商务网站建设与维护 (11)考试考核试题

学生答案：作答 13.一般来说，动态网站均由前、后台组合而成。前台，即网站管理层所用，后台，则是普通用户可见层。（） A.错误 B.正确错误正确答案：学生答案：作答 14.教研室网站的支持企业是北京博导前程信息技术有限公司。（） A.错误 B.正确错误正确答案：学生答案：作答 15.海尔商城的购物要求首先注册成为会员才能进行，整个注册过程比较简单，只需要经过四个步骤即可注册成为会员。（） A.错误 B.正确错误正确答案：学生答案：作答 16.海尔商城电子商务的应用实现企业价值缩减环节，降低成本，收益增加；提供在线帮助，节省管理成本；非核心企业外包，降低库存量，提高收益。实现了从传统零售到电商的一步。（） A.正确 B.错误错误正确答案：学生答案：作答 17.海尔商城，主要功能是向消费者介绍海尔产品。（） A.错误 B.正确错误正确答案：学生答案：作答 18.版面布局的步骤是（） A.构思并绘制草案——定案——粗略布局 B.粗略布局——构思并绘制草案——定案 C.定案——构思并绘制草案——粗略布局 D.构思并绘制草案——粗略布局——定案错误正确答案：学生答案：作答 19.电子商务网站的基本要素主要包括：网站 Logo、网站导航、栏目分类、注册登录、网站
购物流程、用户咨询与论坛管理机制以及网站地图等。（） A.错误 B.正确错误正确答案：学生答案：作答 20.以下哪种页面布局像一张宣传海报，以一张精美图片作为页面的设计中心，常用于时尚类站点（） A.变化型布局 B.POP 布局 C.网页“T”结构布局形式 D.国型布局错误正确答案：学生答案：作答 21.<br>属于以下哪种常用的标记（） A.文字标记 B.换行标记 C.分段标记 D.标题标记错误正确答案：学生答案：作答 22.<div>是一个区域容器标记，即<div></div>之间相当于一个窗口，可以容纳段落、标题、表格、图片等各种 HTML 元素。（） A.错误 B.正确错误正确答案：学生答案：作答 23.CSS 是 Cascding Style Sheet使用 CSS 样式，可将页面的内容与表现形式分离。CSS 文件也可以说是一个文本文件，它包含了一些 CSS 标记，必须使用.css 为文件名后缀。（） A.正确 B.错误错误正确答案：学生答案：作答 24.相对于静态网站而言，网站的测试主要包括以下哪些内容（） A.以上都正确 B.SEO 测试 C.可用性测试 D.浏览器兼容性测试 E.功能性测试

2024年双创知识竞赛题库及答案(共130题)

2024年双创知识竞赛题库及答案（共130题）L互联网+全称是（C）A.中国国际互联网+大学生创新创业大赛B.中国互联网+创新创业大赛C.中国国际“互联网+”大学生创新创业大赛D.中国国际“互联网+”大学生创新创业竞赛2.第九届中国互联网+大学生创新创业大赛承办学校是（D）A.西北工业大学B.西安建筑科技大学C.济南大学D.天津大学3.主赛道包括（A）A.高教主赛道青年红色筑梦之旅赛道职教赛道国际赛道B.高教主赛道青年红色筑梦之旅赛道职教赛道全国赛道C.高教主赛道青年红色筑梦之旅赛道职规赛道国际赛道D.高教主赛道少年红色筑梦之旅赛道职教赛道国际赛道4•高教主赛道参赛组别有（C）A.创意组初创组培养组师生组共创组B.创意组初创组成长组教师组共创组C.创意组初创组成长组师生组共创组D.创意组再创组成长组师生组共创组5.第八届中国国际“互联网+”创新创业大赛主题（C）A.创新引领未来，智慧改变生活B.“互联网+”成就梦想，创新创业开辟未来C.我敢闯，我会创D.敢为人先，勇立潮头6.团队参赛人员（B）A.最少4人，最多12人B.最少3人，最多15人C.最少6人，最多18人D.最少2人。

最多10人7.路演答辩需要多长时间(D)A.8分钟B.7分钟C.6分钟D.5分钟8.第八届互联网+创新创业大赛承办学校是(A)A.重庆大学9.同济大学C.西北大学D.天津大学10“三创赛”全称是(B)A.全国大学生电信商务创新创意及创业挑战赛B.全国大学生电子商务创新创意及创业挑战赛C.全国大学生电子商业创新创意及创业大赛D.全国大学生电子商务创新创意及创业大赛11.挑战杯创青春活动主题是(A)A.青创报国新时代，青春筑梦新征程B.创新引领未来，智慧改变生活C.“互联网+”成就梦想，创新创业开辟未来D.挑战无极限，创新引未来∏∙“挑战杯”全称是(A)A.“挑战杯”全国大学生课外学术科技作品竞赛B. "挑战杯”全国大学生课内学术科技作品竞赛C.挑战杯全国大学生课内学术科技作品竞赛D .“挑战杯”全国大学生课外学术科技项目竞赛12.“挑战杯”简称(A)A.大挑B .小挑C.国挑13.“创青春”全称是（C）A.挑战杯中国大学生创业计划挑战赛B.挑战杯中国大学生创新创业计划竞赛C.挑战杯中国大学生创业计划竞赛D.挑战杯中国国际大学生创业计划竞赛14.“创青春”简称是（B）A.大挑B .小挑C.国挑15.中国“互联网+”大学生创新创业大赛每个团队的参赛成员不少于（B）人，须为项目的实际成员。

尔雅习题：创业创新

如何实现梦想1 【单选题】Facebook的主要创始人是（）A、比尔·盖茨B、马克·扎克伯格C、巴菲特D、乔布斯我的答案：B 得分：33.3分2 【单选题】凭借互联网创业成功的企业家不包括（）A、马云B、马化腾C、李彦宏D、王健林我的答案：D 得分：33.3分3 【判断题】胡润榜被广泛认为是追踪记录中国艺术家群体变化的权威机构我的答案：×如何进行非常规自我实现1 【单选题】美国通用电器的创始人是（）A、爱迪生B、洛克菲勒C、福特D、爱因斯坦我的答案：A2 【单选题】将整合网上海量信息作为自己远大目标的企业是（）A、苹果B、百度C、谷歌D、阿里巴巴我的答案：C 得分：33.3分3 【判断题】中国的应试教育多注重考试能力而忽视做事能力我的答案：√执行力的重要性1 【单选题】开放文明环境地图主要关注的是（）A、经济发展B、文化教育C、军事前沿D、生态现状我的答案：D 得分：33.3分2 【单选题】开辟了横渡大西洋到美洲航路的航海家是（）A、达·伽马B、麦哲伦C、哥伦布D、郑和我的答案：C 得分：33.3分3 【判断题】哥伦布将发现的非洲大陆误认为是印度。

（）我的答案：×如何鼓励创新1 【单选题】工业革命时期的现代学校起源于（）A、法国B、美国C、中国D、德国我的答案：D2 【判断题】现有的学校教育制度是工业革命的产物我的答案：√与学生关于梦想实现的互动1 【单选题】出自犹太民族的历史精英不包括（）A、爱因斯坦B、马克思C、冯诺依曼D、列宁我的答案：D 得分：50.0分2 【单选题】比尔·盖茨和艾伦创造了（）A、标准石油公司B、微软公司C、肯德基公司D、可口可乐公司我的答案：B对学生关于梦想实现的解答1 【单选题】美国著名的纯电动车制造商是（）A、大众汽车公司B、克莱斯勒汽车公司C、特斯拉汽车公司D、福特汽车公司我的答案：C2 【单选题】因在牛奶中掺加三聚氰胺而破产的国内企业是（）A、三鹿集团B、蒙牛公司C、伊利公司D、三元集团我的答案：A 得分：33.3分3 【判断题】在目前中国的教育体制下，学生追求自己的梦想往往要担负很大的风险我的答案：√课程教学方法的简介1 【单选题】由苹果公司开发的移动操作系统是A、Android B、IOS C、SymbianD、Windows Phone 我的答案：B 得分：33.3分2 【单选题】我国目前最大的非营利性民间环保组织是A、中国爱心网B、国家地理C、自然之友D、幸福家园我的答案：C3 【判断题】互联网的核心和基础是物联网我的答案：×事件营销案列的解析1 【单选题】2011年在大地震中受损而引发核泄漏的是（）A、德国的比布利斯核电站B、法国马库勒核电站C、美国贝尔丰特核电站D、日本福岛核电站我的答案：D 得分：33.3分2 【单选题】徐霞客是我国历史上著名的（）A、历史学家B、地理学家C、天文学家D、教育家我的答案：B 得分：33.3分3 【判断题】著名天使投资人薛蛮子是搜狐大V 我的答案：×关于公益组织的营销思路1 【判断题】目前我国高校社团在开展活动中的创新性不足我的答案：√得分：100.0分如何在实践中挖掘自身潜能1 【单选题】下面不属于社交媒体营销的是（）A、人人网营销B、展会营销C、微博营销D、微信营销我的答案：B 得分：33.3分2 【单选题】敢于“反其道而思之”，让思维向对立面的方向发展的是（）A、直观动作思维B、形象思维C、抽象逻辑思维D、逆向思维我的答案：D 得分：33.3分3 【判断题】谷歌地图还不能覆盖农村范围我的答案：×师生公益项目的实际案例1 【单选题】2013年发生在北京的引人关注的天气事件是（）A、雪灾B、雷暴C、雾霾D、泥石流我的答案：C 得分：33.3分2 【单选题】PM2.5测试仪的网络连接形式不包括（）A、3G网络连接B、有线连接C、WIFI连接D、WCDMA连接我的答案：D3 【判断题】云传感器是物联网时代的产物我的答案：√学生对公益项目的进程总结1 【单选题】完成产品的性能设计、使用方便性的设计后其次应该考虑A、产品的外观B、产品的环保性能C、产品成本D、以上答案都正确我的答案：C2 【判断题】设计产品时在产品的性能和实用方便性方面应该优先考虑产品的性能要求我的答案：×谷歌开发社区团队的案例1 【单选题】谷歌中国开发者社区论坛的简称是（）A、EOE社区B、GDG社区C、ROM社区D、水木社区我的答案：B2 【单选题】ROM社区用户的构成不包括（）A、软件人员B、大学生C、IT 业人士D、农场主我的答案：D 得分：33.3分3 【判断题】目前互联网图像数据是急需极大丰富的。

2020年智慧树知道网课《大学生创新创业基础(西安铁路职业技术学院)》课后章节测试满分答案

第一章测试1【单选题】(20分)创新活动的基础和开端是（）A.管理创新B.观念创新C.方法创新D.制度创新2【单选题】(20分)12306推出的候补购票功能属于（）创新？A.产品创新B.技术创新C.服务创新D.组织创新3【多选题】(20分)创新的主要类型是（）A.有中生无B.无中生有C.创意设计D.创业实践4【多选题】(20分)创新的普遍性原理包含：A.物物皆可创新B.时时皆可创新C.人人皆可创新D.处处皆可创新5【判断题】(20分)创新的两个主要特征是新颖性和价值性。

A.错B.对第二章测试1【判断题】(10分)心智模式总是阻碍人们的思维创新，因此应该摒弃。

A.错B.对2【单选题】(10分)“政治理论学习往往枯燥无趣”产生这样的心智模式根源是（）A.直接经验B.归纳C.推理D.间接经验3【单选题】(10分)影像巨头柯达公司退出人们的视野最主要的原因是（）A.从众思维B.拒绝变化C.D.经验思维4【判断题】(10分)2008年成立的Airbnb作为一家服务型网络平台能够取得巨大的成功，其中非常重要的因素之一就是突破了思维定式。

A.对B.错5【单选题】(10分)“共享”概念一经提出，市场上出现了非常多的产品共享，这是典型的（）思维？A.从众思维B.惯性思维C.D.逆向思维6【判断题】(10分)人们口中经常提到的“天下乌鸦一般黑”是由于思维视角的不同所导致的。

A.对B.错7【单选题】(10分)“马应龙”牌口红的出现是突破思维障碍中（）策略的体现？A.转变观念B.转变视角C.转变方向D.转变方法8【单选题】(10分)选择题：一加手机携手韩寒玩“自黑”的广告是运用了（）思维来突破传统模式？A.侧向思维B.发散思维C.逆向思维D.联想思维9【判断题】(10分)原本以卖鱼为盈利点结果转向捕鱼观光获得巨大收入是合理运用侧向思维的结果。

A.错B.对10【判断题】(10分)转换视角的前提要懂得换位思考。

A.错B.对第三章测试1【单选题】(20分)下列说法不正确的是A.代表客观事实和数字的是白色思考模式B.带上黄色思考帽，人们需要从正面考虑问题C.红帽这种思考模式要避免过度的使用D.黑色代表的是光明与肯定2【判断题】(20分)发散思维又称作辐射思维，扩散思维或者多路思维。

你如何看待报网融合？

你如何看待报网融合？我认为报网融合是当前媒体行业发展的一个重要趋势，具有一定的优势和挑战。

以下是我对报网融合的看法：优势：1.多渠道传播：报网融合使得传统报纸和互联网媒体能够通过多个渠道同时发布内容，满足不同用户的需求。

这种多渠道传播可以扩大内容的覆盖范围，提高信息传播的效率。

2.互动与个性化：报网融合可以提供更多的互动性和个性化服务。

通过互联网平台，用户可以以更多的形式与媒体互动，例如评论、分享、订阅和参与讨论等。

媒体也可以根据用户的兴趣和偏好，提供定制化的内容推荐，增强用户体验。

3.多媒体表达：互联网技术使得报网融合能够更好地以多媒体形式表达信息。

除了文字报道，通过图片、音频、视频等多媒体手段，媒体可以更直观地呈现事实和观点，提高信息的传播效果。

挑战：1.商业模式转型：报网融合对传统报纸业务模式带来了巨大的冲击。

传统报纸面临着纸质媒体阅读率下降、广告收入减少等问题，需要积极探索新的商业模式和盈利方式。

2.内容质量和可信度：互联网上的信息呈现爆炸式增长，把握内容质量和可信度成为一个重要的挑战。

媒体在报网融合过程中需要关注事实核查、新闻伦理和道德，以保持内容的质量和可信度。

3.竞争加剧：报网融合使得互联网媒体之间的竞争加剧。

传统报纸要与互联网纯数字媒体进行竞争，需要不断提升自身的媒体品质、创新能力和用户体验，以保持竞争力。

总体而言，报网融合是媒体行业不可避免的趋势，可以提供更广泛的传播渠道、更好的用户互动和个性化服务，但也面临着商业模式转型、内容质量和竞争加剧等挑战。

媒体需要积极适应这一趋势，不断创新和改进，以适应快速变化的媒体生态。

第八组好孩子网和红孩子网SWOT分析

好孩子网与红孩子网的SWOT分析
第八组：简耔、大只蛙、猪屎欣、黎B 、猪玲、碧哥
正文：
易观国际认为，红孩子在2006到2007年两年中，凭借资本的推动，可以实现在全国各地域市场的尽快布局，以迅速树立市场规模和用户规模的竞争优势；另一方其发展方向将是横向实现起商品品类的扩充，以满足客户的更多需求。

易观国际建议红孩子：经过快速的扩张之后，深根细作是必不可少的。

快速扩张会带来管理成本的迅速增长，并且存在管理效率和效果下降的风险，巩固地方市场，加强各地域市场活跃用户的开发与培养将是红孩子之后的发展重点。

1999年12月“好孩子”商标被国家工商总局评定为中国驰名商标。

“好孩子”品牌成为唯一能在世界儿童用品领域产生广泛影响的中国品牌。

好孩子集团创立于1989年，行业先进的婴儿推车供应商、专业母婴产品分销零售平台、著名婴幼儿用品全面解决方案提供商。

安全、耐用、时尚、关爱是品牌四大核心价值。

更有好孩子科学育儿网，让父母轻松享受育儿全过程。

好孩子儿童用品有限公司主要产品：婴儿推车、自行车、学步车、三轮车、。

第5章垂直模式[35页]

第5章垂直模式
引例——垂直电商崛起，大众电商让路
从每年销售额的增量来看，我们似乎有理由相信，以淘宝天猫为主的大众电商平台，正在清洗甚至屠宰传统的线下产业。马云在和万达老板王健林的世纪对赌当中，也信心满满，对大众电商逐渐取代线下传统门店的趋势仿佛胜券在握。
当年国美苏宁两个家电连锁平台血洗传统家电百货商场的时候，黄光裕似乎也信心满满，认为国美一统家电市场的江湖似乎指日可待，没想到好日子不长久，京东电商平台侧翼出击，出奇制胜，严重分流了家电的消费市场。
➢ 垂直电商定位于客户群体时，需要回答企业正在为谁创造价值？谁是企业重要的客户？一般而言，垂直电商主要是基于特定细分市场的客户群体，即为某一特定市场的客户提供价值，设计满足客户要求的产品或服务。
5.2.1 客户定位
➢ 例5-3 聚美优品：聚集美丽
拿聚美优品来说，自2010年3月开团以来，聚美优品就以中国第一家专业的化妆品团购网站的市场定位，秉承用户至上、品质第一的价值观，以‘聚集美丽，成人之美’的理念，聚集爱美女性，聚集各种让女性美丽的优良产品。从聚美优品的市场定位和企业理念、服务宗旨看出，聚美优品创立之优品网站的女性用户约占70%，男性约占30%。访问网站的大部分人群为女性，且年龄主要聚焦于20-39岁的群体，其中20-29岁为最核心用户。
➢ 1.垂直电商的定量价值主张定量价值主张主要聚焦于为客户提供可量化的、可见的价值。垂直电商主要借助于较低的价格和
定制化的产品。 ➢ 2.垂直电商的定性价值主张
用户体验是一种新颖消费模式，由消费者先行试用商品，通过直接体验感受商品使用，从而引领新商品的消费。
启示：综合性的电商平台已经崛起，而随着移动互联技术的升级与变革，垂直电商的兴起必然成为一个趋势。

新疆和田地区全员教师数字素养提升专项培训结业测试答案

1.数字化课程内容的设计课程的学习不局限于课堂, 也可以在课后, 学生可以使用手机、平板电脑等终端设备下载、缓存, 更灵活, 方便学生在任何地方、任何时间进行学习, 摆脱了时间与空间的束缚。

（3分）对2.精准D课堂的课中课后需要借助上城课堂观察室形成数据、分析数据，反刍课堂改进。

（3分）对3.“双减”工作强调要科学利用课上时间，开展阅读活动。

（3分）错4.智慧教育云平台最核心的模块是数字教学空间，数字教学空间与物理教学空间教学活动一体化设计正在成为常态对5.教育与游戏历史上一直处于分离状态，难以融合。

错6.美国新媒体联盟是一个关注新媒体、新技术在各类教育中应用，具有全球影响力的非盈利机构，致力于为学习、研究和创新来探索和开发新兴技术。

对7..人工智能时代，学生才是综合评价的主体。

错8.广义的游戏化学习是指将游戏尤其是数字游戏用到学习中，狭义上的游戏化学习是指将游戏元素和机制应用到学习情境或学习过程中。

（错）9.教育部发布哪个行业标准规定了教师在教育数字化转型过程中专业发展的具体指标（3分）《教师数字素养》10.当下应用最广泛的游戏一般式较大型的角色扮演游戏，因为这类游戏趣味性、参与度更强。

错11.数字化课程内容的设计课程的学习不局限于课堂, 也可以在课后, 学生可以使用手机、平板电脑等终端设备下载、缓存, 更灵活, 方便学生在任何地方、任何时间进行学习, 摆脱了时间与空间的束缚。

错12.体验式学习是以学生为主体，强调学生在学习活动中的主动性，通过创设智慧场馆，形成让学生在真实情境中获得直接体验的学习方式。

对13.人工智能与课堂教学有机融合，创新教学模式，提供个性化教学平台，有助于提高学生借助技术开展学习与交流的能力。

对14.互补型混合式教学基本模式是指线上提供各种学习资源让学生进行自学，线下个别化辅导。

错15.数字化课程可以按目标、内容、功能分类。

对16.国新媒体联盟是一个关注新媒体、新技术在各类教育中应用，具有全球影响力的非盈利机构，致力于为学习、研究和创新来探索和开发新兴技术。

Accelerating Taub-NUT and Eguchi-Hanson solitons in four dimensions

a rXiv:g r-qc/6892v 119Aug26gr-qc/yymmxxx Accelerating Taub-NUT and Eguchi-Hanson solitons in four dimensions Brenda Chng,1Robert Mann 2and Cristian Stelea 31Department of Physics,National University of Singapore 2Science Drive 3,Singapore 1175422Perimeter Institute for Theoretical Physics 31Caroline St.N.Waterloo,Ontario N2L 2Y5,Canada 2,3Department of Physics,University of Waterloo 200University Avenue West,Waterloo,Ontario N2L 3G1,Canada Abstract We construct new solutions of the vacuum Einstein ﬁeld equations in four dimen-sions via a solution generating method utilizing the SL(2,R )symmetry of the reduced Lagrangian.We apply the method to an accelerating version of the Zipoy-Voorhees solution and generate new solutions which we interpret to be the accelerating versionsof the Zipoy-Voorhees generalisation of the Taub-NUT solution (with Lorentzian sig-nature)and the Zipoy-Voorhees generalisation of the Eguchi-Hanson solitons (with Euclidean signature).As an intermediary in the solution-generating process we obtain charged versions of the accelerated Zipoy-Voorhees-like families of solutions.Finally we present the accelerating version of the Taub-NUT solution and discuss its properties.PACS:04.20.-q,04.20.Jb,04.50.+h1IntroductionEver since the formulation of General Relativity,exact solutions have played an integral part in our understanding of the nature of spacetime.For example,much of our understanding of black hole thermodynamics and inﬂation were possible only with the discovery of the Kerr-Newman and FRW solutions respectively.Given the importance of such exact solu-tions,there is a corresponding impetus to derive new solutions which upon analysis would yield further insight into our universe.Since Einstein’s equations in their unadulterated form consist of a series of coupled non-linear diﬀerential equations,obtaining solutions by hand is intractable unless some kind of simplifying symmetry is imposed in the ansatz.This motivated the development of many ingenious and powerful strategies utilizing such simpliﬁ-cations to derive solutions to Einstein’s equations.Of particular importance for the present work is a special type of simplifying ansatz,the static axisymmetric Weyl-Papapetrou metric, which wasﬁrst proposed by Weyl in[1]ds24=−e−ψdt2+eψ e2µ(dρ2+dz2)+ρ2dϕ2 .(1) The metric is speciﬁed by the values of two functionsψandµ,which are functions of the canonical Weyl variablesρand z.Starting with a static vacuum axisymmetric solution of the Einsteinﬁeld equations,consider its dimensional reduction along the timelike direction down to three dimensions.The reduced Lagrangian can be written as:L3=eR−1g and R is computed with the three-dimensional metric:ds2=e2µ(dρ2+dz2)+ρ2dϕ2.(3) The equation of motion forψis then readily seen to be∆ψ=0,where∆is the Laplacian constructed using the three-dimensional metric(3).Now,the key observation is that∆ψ= e−2µ∆µ=0ψ,where∆µ=0is the Laplacian computed for aﬂat three-dimensional Euclidean metric,which corresponds to settingµ=0in(3).Therefore any solutionψ(ρ,z)of Laplace’s equation in theﬂat three dimensional space is automatically a valid solution of Laplace’s equation in the curved background(3).Once we knowψ,the remaining functionµ(ρ,z)is found by performing a simple line-integral using the relations:∂zµ=ρ4 (∂ρψ)2−(∂zψ)2 .(4)The Einstein’s equations in4-dimensions for a static axisymmetric background are now es-sentially reduced toﬁnding a solution of Laplace’s equation onﬂat space.Due to the linearity of the Laplace equation forψ,construction of multi-black hole versions is easily carried out. The Weyl formalism has been recently extended to higher dimensions by Emparan and Re-all[2]and the same line of thought can be used for the corresponding higher dimensional axisymmetric metrics.Given the simpliﬁcations introduced by the above axisymmetric ansatz,one now has two choices.One may either try to solve the diﬀerential equations directly,or,in more generalcases,try to further exploit the hidden symmetries of the dimensionally reduced Lagrangians and generate solutions using pre-existing solutions as seeds.Consider for instance the following‘scaling’symmetry of theﬁeld equations:given a vacuum static solution described by the pair of functions(ψ,µ)then it is easily seen from (4)that the pair(γψ,γ2µ)will describe new vacuum static axisymmetric solution of the ﬁeld equations,whereγis any real parameter.As an example,its application converts the Schwarzschild solution into the Zipoy-Voorhees solution[3].This simple observation will be liberally utilised in the present work.There also exist transformations similar to the Ehlers-Harrison transformation for the Ernst formalism[4,5,6]which map static vacuum solutions into stationary Einstein-Maxwell solutions.For the Weyl-Papapetrou ansatz,it has been long known that a transformation al-ready exists that brings a static,axisymmetric vacuum solution to a non-trivial class of static solutions in Einstein-Maxwell theory[7].In particular,the Schwarzschild solution can be transformed into the Reissner-Nordstr¨o m solution.In this paper,we will demonstrate a sim-pler alternative derivation of this transformation using a SL(2,R)symmetry of the reduced Lagrangian in three dimensions.1However,unlike previous applications of this transforma-tion,we show that combining this transformation with the above scaling symmetry,we are able to generate new solutions.Our seed metric will be an accelerating version of the Zipoy-Voorhees solution[9].In particular,we obtain new vacuum stationary axisymmetric metrics which we interpret as describing the accelerating Zipoy-Vorhees-like family of Taub-NUT solutions(with Lorentzian signature)and Eguchi-Hanson instantons(with Euclidean signa-ture).Much like the original Zipoy-Voorhees solution[3],such metrics are parameterized by a real numberα.Forα=1we recover the accelerating Taub-NUT/Eguchi-Hanson solitons and,for higher positive integer values ofα,they can be interpreted as the‘superposition’of acceleratingαNUT-charged objects/solitons.The structure of this paper is as follows.In section2we describe our solution generating technique,which maps a static axisymmetric solution in vacuum to a new stationary vacuum solution of Einstein’s gravity in four dimensions.In section3we apply the transformation technique on accelerating solutions,namely on the C-metric and on the accelerating Zipoy-Voorhees metric and we consider more closely the properties of the generated accelerating Taub-NUT solution in section4.Finally,in section5we summarise the main results of this paper and discuss potential avenues for further research.In Appendix A we cast the accelerating Taub-NUT metric in Weyl-Papapetrou form.2Weyl’s charging method:the SL(2,R)approachWe start with Einstein-Maxwell theory in four dimensions described by the Lagrangian:L4=eR−11A similar idea has been considered in[8],however the details of the charging transformation diﬀer here.denote e=√2e(∂φ)2+12χ2χ2−e−φ4eφ4C2δ,χ=4Cδr dt2+dr2r+r2(dθ2+sin2θdϕ2).(13) |g|and R is computed with the3-dimensional metric ds23.Theﬁnal solution can be written in the form:ds2=−4C2δr(r−2m)4C2δr(r−2m)dr2+((1−δ)r+2δm)2(1−δ)r+2δmdt.(14)For generic valuesδ=1we can easily perform a redeﬁnition of the radial coordinate,together with an appropriate constant scaling of the timelike coordinate and cast the solution into the usual Reissner-Nordstr¨o m form.The electric charge is Q=m/C,while the mass of the solution is M=(1+δ)Q/(2√2e(∂φ)2−13.To do this we shall employ the general results derived in[11](see also[12]for a geometrical derivation of the respective mapping).Starting with a magnetostatic solution:ds24=−e−φdt2+eφ e2µ(dρ2+dz2)+ρ2dϕ2 ,A(1)=Aϕdϕ,(17)the corresponding solution of the EMD system is:ds 24=−e−φ4 e 2µ 12dϕ,e ˜φ3=e φ√2dϕ)2+e ˜φ3ds 24.(19)In our case it turns out that the 5-dimensional metric is simply the trivial product of a 4-dimensional Euclidean metric with a time direction.Since the 5-dimensional metric solves the vacuum Einstein equations it is manifest that the 4-dimensional Euclidean metric will be Ricci ﬂat,i.e.it solves the vacuum Einstein equations in four dimensions.Therefore,our ﬁnal result is expressed in the form:ds 24=e −φ2 e 2µ 12it is easilyseen that we obtain an axisymmetric NUT-charged solution with naked singularities,whose physical interpretation is obscure at this point.On the other hand,since we restrict ourselves to axisymmetric metrics that can be cast in Weyl form,it turns out that before we apply the charging procedure one can use the scaling symmetry discussed in introduction to scale the dilaton in the initial seed in such a way to cancel the awkward eﬀect of the square-roots in the ﬁnal expression of the metric.3Accelerating Zipoy-Voorhees-like families of solutions In four dimensions,a particularly interesting class of solutions that generalise the Schwarzschild black-hole is the so-called C-metric.The static part of this metric was found by Levi-Civita almost one century ago (see[6]),however,its physical interpretation was clariﬁed only af-ter Kinnersley and Walker’s work decades later [13].By performing appropriate coordinate deﬁnitions,they found that this metric describes a pair of causally disconnected black holes uniformly accelerating in opposite directions.The cause of the acceleration is understood in terms of nodal/conical singularities along the axis that connects the two black holes andthese singularities are interpreted as strings/struts pulling or pushing the black holes apart.A more general class of electrovacuum spacetimes that includes and considerably generalisesthe C-metric was found by Pleba´n ski and Demia´n ski[14](see also in[15]thegeneral Type Dfamily of solutions in EM theory).Recent analyses of this class of solutions have been per-formed in[16,17],where a new exact solution describing a pair of accelerating and rotating charged black holes having also a NUT-charge has been presented.However,an accelerating NUT solution without rotation has not been identiﬁed yet within that class[17].It is the goal of this section to try to construct such an accelerating solution.We shall consider next the uncharged C-metric,respectively the accelerating Zipoy-Voorhees solution[9]as the seeds in our solution-generating procedure.Expressed in the form given in[16]the C-metric takes the simple form:ds2=1(y2−1)F(y)+dx22mA≤y≤−1,−1≤x≤1.(21)In terms of these coordinates,spatial inﬁnity corresponds to x=y=−1,the black hole horizon is located at y=−1A2(x−y)2,e2µ=(y2−1)F(y)A4(x−y)4,z=(1−xy)[1+mA(x+y)]A4(x−y)4 dy2(1−x2)F(x).(24)Consider now the scaling transformation (ψ,µ)→(γψ,γ2µ),where γis a real parameter.Applying it to the C-metric we obtain a new vacuum solution of the form:ds 2=− (y 2−1)F (y )[(y 2−1)F (y )]γ−1dϕ2+((y 2−1)F (y ))γ2−γ(y 2−1)F (y )+dx 2Ar ,t →A 2γ−1t,(26)while taking the limit A →0and rescaling the metric by a constant factor A 2γ−2it is readily seen that we recover the Zipoy-Voorhees solution ([3]).Therefore,one could naively interpret the metric (25)as describing an accelerating version of the Zipoy-Voorhees solution.However,the fact that the above metric is not the ‘proper’accelerating Zipoy-Voorhees solution can also be seen from the fact that the γ=2of this family should reduce to the so-called accelerating Darmois solution.This is the coincident limit of the accelerating Bonnor dihole solution that was recently found by Teo in [9].In fact,a diﬀerent metric describing the accelerated Zipoy-Voorhees solution,however,written in a very symmetric form has been presented by Teo in the same work.The ‘proper’accelerating Zipoy-Voorhees solution reads:ds 2=−e −ψdt 2+e ψ e 2µ(dρ2+dz 2)+ρ2dϕ2 ,(27)e −ψ=(y 2−1)F (y )F (x ) α−1,e 2µ=(y 2−1)F (y )G (x,y )α2−1,where the canonical Weyl coordinates are again deﬁned in (24).Indeed,we see that the Darmois solution (i.e.the α=2member of this family)is clearly diﬀerent from the γ=2member of (25)and therefore we cannot actually interpret (25)as being an accelerating version of the Zipoy-Voorhees family.4Nonetheless,since the metric (25)is only an interme-diate result in our solution-generating technique,we shall not further discuss its properties at this point,but limit ourselves to notice that one can apply the scaling transformation on Teo’s solution and further generate a new family of vacuum metrics indexed by two distinct real parameters:ds 2=−e −ψdt 2+e ψ e 2µ(dρ2+dz 2)+ρ2dϕ2 ,(28)e −ψ= (y 2−1)F (y )F (x ) α−1 γ,e 2µ= (y 2−1)F (y )G (x,y )α2−1 γ2,The next step is to charge the solution(28)using a general SL(2,R)transformation. Using the formulae(12)we obtain:ds2=−e−ψ1A2(x−y)2F(y) α−1 γ−δdt,Hγ(x,y)=1−δ (y2−1)F(y)F(x) α−1 γ 2C (1−x2)(αF(x)+(1−α)F(y))AC,(29)while the metric remains unchanged in this process.Finally,takingγ=2and using(20)we ﬁnd:ds4=(y2−1)F(x)F(x) αC2δA2(x−y)2F(x)G(x,y)α2−1 dy2(1−x2)F(x),(30)where we deﬁned:H(x,y)=1−δ (y2−1)F(x)F(x) α 2Ar ,δ→δA4,t→twe obtain a general family of vacuum Euclidean solutions,indexed by a real parameter α,5which interpret as the Zipoy-Voorhees generalisation of the Eguchi-Hanson soliton:ds 2=1−δ 1−2m 1−2m (r −m )2−m 2cos 2θ α2−1(dr 2+r (r −2m )dθ2)+r (r −2m )sin 2θdϕ2 +4C 2δ 1−2m 1−δ 1−2m C cos θdϕ)2.(33)Indeed,if we take α=1and properly rescale the z coordinate to absorb some constant factor we obtain a spherically-symmetric metric:ds 2=δr (r −2m )r (r −2m )+d Ω2 .We distinguish now two possibilities.If we set directly δ=1we can cast the metric in the following form:ds 2=R 2R 4(dz +cos θdϕ)2+dR 2R 4+R 2√δ R +nδ R +n√r 2αr αr (r −2m )rαr 2α(dt +2mα5Notice that C is not an essential parameter and it can be absorbed by a constant rescaling of the z coordinate.6We also changed the notation z →t .(1+δ)N 2=4δm 2,we obtain:ds 2=− R ±N δ R ∓N √R 2+N 2(dt +2N cos θdϕ)2+R 2+N 2√δdR 2+(R 2+N 2)d Ω2,i.e.the Taub-NUT solution [20]with mass M =±N (δ−1)δand NUT charge N .On the other hand,setting δ→0and taking the limit C →∞while keeping the product C 2δconstant,the metric (34)is readily seen to reduce to the Zipoy-Voorhees metric.Therefore,we expect that (30)describes the accelerating version of the family (33).Computing some of the curvature invariants for this metric one ﬁnds that generically there is a curvature singularity located at the roots of H (x,y )=0as long as x =y .However if we consider negative values of δ(i.e.replace δ→−δ)in the above metric we obtain a vacuum solution with Lorentzian signature and furthermore,we ﬁnd that H (x,y )>0always (for x =y ).4Properties of the accelerating Taub-NUT solution In what follows we will concentrate our attention on the α=1member of this Lorentzian family.The metric becomes:ds 4=−(y 2−1)F (y )H (x,y ) dt +1A 2(x −y )2+2mx A 2(x −y )2 (1−x 2)F (x )dϕ2+dy 2(1−x 2)F (x ),(35)where we denote:H (x,y )=1+δ (y 2−1)F (y )2.Let us ﬁrst notice that the C-metric,respectively the Taub-NUT metric are included as limiting cases in the above solution.Indeed,taking δ→0and C →∞while keeping the product C 2δconstant,after rescaling the time coordinate with a constant factor we obtain the uncharged C-metric solution.On the other hand,the zero-acceleration limit is taken by performing the coordinate redeﬁnitions and scalings of the parameters:x =cos θ,y =−1A,(36)in the limit A →0.It is readily seen that in this limit we obtain the Taub-NUT metric.To understand the properties of this solution it turns out to be more convenient to consider the above metric in Weyl form:ds 2=−e −φ(dt +A ϕdϕ)2+e φ e 2µ(dρ2+dz 2)+ρ2dϕ2 ,e −φ=e −ψ2C 2δf (x,y )G (x,y ),(37)where the canonical Weyl coordinatesρand z are given by(24)and the expressions of e−ψand e2µin terms of the canonical Weyl coordinates are given in Appendix A.The general analysis of the above metric can now be done in parallel with the one corresponding to the uncharged C-metric.In particular,we see that if we restrict the values of m and A such that 0≤2mA<1,then,in order to preserve the correct signature of the metric,the coordinates (x,y)have to take the range:−1≤x≤1,−12mA and y=−1.Aswe shall prove bellow,y=−12mA =−m2mA =m2A2.Note now that e−φ|ρ=0vanishes at all the above points z i,i=1..3,it is positive for z<z1 and z2<z<z3whereas both e−φ|ρ=0and e2µ|ρ=0are zero for z1<z<z2and z>z3. We may then follow a similar analysis with the one performed in[21]to conclude that the regions z1<z<z2and z>z3are the Killing horizons of our accelerating solution.One can also see this by noting that the location of the horizons is given by the equation g yy=0, which in our case corresponds to the equation(y2−1)F(y)=0.Furthermore,by computing the area of each of the above horizons one can check that z1<z<z2hasﬁnite area and it corresponds then to a black hole horizon,while z>z3has inﬁnite area and it corresponds to an accelerating horizon.Indeed,using the C-metric coordinates the area of the black hole horizon is readily found to be:A H= 2π0 1−1√C√is positive,e−φ>0,the deﬁcit of conical angle will be given by7:∆=2π−∆ϕe−µ|ρ=0.(40) Recall that if∆<0one has an excess of conical angle and this corresponds to a strut,if ∆>0one has a deﬁcit of conical angle that corresponds to a string,whereas if∆=0there is no conical singularity on that part of the symmetry axis.Since in our case the function e2µis precisely the same with the one corresponding to the uncharged C-metric,we deduce that in general there is a conical singularity residing in this solution and that,for appropriate values of∆ϕ,it can be chosen to lie along z2<z<z3(i.e.x=1)or z<z1(i.e.x=−1). In particular weﬁnd:∆x=±1=2π−(1±2mA)∆ϕ.(41) One can remove the conical singularity on the segment z2<z<z3(i.e.x=1)if one chooses∆ϕ=2π/(1+2mA)but then there will be a positive deﬁcit angle for z<z1 (i.e.x=−1)and this can be interpreted as an semi-inﬁnite cosmic string pulling on the black hole.Alternatively,for∆ϕ=2π/(1−2mA)one can eliminate the conical angle for z<z1(i.e.x=−1)but then there will be a excess of conical angle for z2<z<z3(i.e. x=1).This is interpreted as a strut pushing on the black hole.The strut continues past the acceleration horizon and connects with the mirror black hole on the other side of it.8 Following the discussion in[16]let us consider next the presence of torsion singularities. In general these appear when the conical singularities possess a non-zero angular velocity, signiﬁed by a non-vanishingω=g tϕ/g tt along the symmetry axis.As is apparent from metric written in Weyl-Papapetrou form,near the symmetry axisρ→0for a non-zero value ofωthe coordinateϕwill become a timelike coordinate and this will lead to the apparition of CTCs suﬃciently close to the axis.In general,these CTCs can be eliminated only whenωtakes the same constant value along the entire axis of symmetry as in that case it is possible to perform a global coordinate transformation t→t−ω|ρ=0ϕto give a metric without such pathologies.For our accelerating NUT solution weﬁnd that on the symmetry axisρ=0:ω|x=±1=±2mAC ϕon the linex=1respectively t S=t−2m7The measurement of the proper circumference and proper radius must be performed in a frame for which the proper time dτ=dt+Aϕdϕ=0.8The existence of the second black hole on the other side of the acceleration horizon is obscured by the use of the Weyl coordinates.sionally reduced action in three dimensions.Our method was based on the simple observation that a static axisymmetric metric as written in Weyl-Papapetrou exhibits a simple‘scaling’symmetry that allows one to generate a family of new static vacuum axisymmetric solu-tions,indexed by a real parameter.In particular,using this scaling symmetry one can easily generate the Zipoy-Voorhees solution from the Schwarzschild solution.We also made use of a charging method for static vacuum metrics,which dates back to Weyl[1].We demonstrated a simpler alternative derivation of this transformation by using a SL(2,R)symmetry of the reduced Lagrangian in three dimensions.However,unlike previous applications of this transformation,we showed that with our simpliﬁed mapping and by combining this charging method with the scaling property,one is able to generate new vacuum stationary axisymmetric metrics.The Lorentzian version of the generated solutions gives a Zipoy-Voorhees like generalisation of the accelerating Taub-NUT solutions,while the Euclidean version gives a non-trivial two-parameter generalisation of the Eguchi-Hanson solitons in four dimensions.We focused our attention on a particular member of this family and we showed that it describes the accelerated version of the Taub-NUT space.As avenues for further research,it would be interesting to study in more detail the connection of the singular charged C-metric that we obtained with the usual form of the C-metric.In particular,it would be interesting toﬁnd a proper dilatonic generalisation of the accelerated Zipoy-Voorhees metric,one that would reduce to the proper charged C-metric in the appropriate limit.AcknowledgementsC.S.would like to thank Edward Teo for valuable remarks on the manuscript.B.C.would like to thank Kenneth Hong for his comments on the draft.The work of R.B.M.and C.S.was supported by the Natural Sciences and Engineering Research Council of Canada.A:The Weyl form of the accelerating Taub-NUT metric Following Emparan and Reall[2]we introduce the notation:ζi=z−z i,R i=A2(x−y)2,R1+ζ1=(1−x2)F(y)A2(x−y)2,R2+ζ2=−(x+1)(y−1)F(y)A2(x−y)2,R3+ζ3=−(x+1)(y−1)F(x)2A4(x−y)2,Y13=(x−1)(y−1)F(x)F(y)A4(x−y)2.Then the Weyl form of the uncharged C-metric corresponds to the following expressions: e−ψ=(R1−ζ1)(R3−ζ3)4(2mA−1)2R1R2R3Y12Y23R2−ζ2,(A-3)from which we can readilyﬁnd e−φin(37).Finally,expressing x in terms ofρand z weﬁnd [16]:Aϕ=1R3−ζ3+2m2F0 ,(A-4)where:F0=4m2AR1+m(1+2mA)R2+m(1−2mA)R3,F1=−4mR1−2m(1+2mA)R2+2m(1−2mA)R3,F2=2m[10]B.Bertotti,Phys.Rev.116,1331,(1959);I.Robinson,Bull.Acad.Polon.Sci.7351(1959).[11]R.Emparan and E.Teo,Nucl.Phys.B610,190(2001)[arXiv:hep-th/0104206].[12]B.Chng,“Black diholes revisited”,MSc Thesis,National University of Singapore(un-published).[13]W.Kinnersley and M.Walker,Phys.Rev.D2(1970)1359.[14]J.F.Plebanski and M.Demianski,Annals Phys.98,98(1976).[15]R.Debever,N.Kamran and R.G.McLenaghan,J.Math.Phys.bf261955(1984).[16]K.Hong and E.Teo,Class.Quant.Grav.20,3269(2003)[arXiv:gr-qc/0305089].K.Hong and E.Teo,Class.Quant.Grav.22,109(2005)[arXiv:gr-qc/0410002]. 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