运筹学
要求：
一、独立完成，下面已将五组题目列出，请按照学院平台指定
．．的做题组数作
答，
每人只
．．．．，满分100分；
．．．答．一组题目
．．．．，多答无效
平台查看做题组数操作：学生登录学院平台→系统登录→学生登录→课程考试→离线考核→离线考核课程查看→做题组数，显示的数字为此次离线考核所应做哪一组题的标识；
例如：“做题组数”标为1，代表学生应作答“第一组”试题；
二、答题步骤：
1.使用A4纸打印学院指定答题纸（答题纸请详见附件）；
2.在答题纸上使用黑色水笔
．．作答；答题纸上全部信息要求手
．．．．按题目要求手写
写，包括学号、姓名等基本信息和答题内容，请写明题型、题号；
三、提交方式：请将作答完成后的整页答题纸以图片形式依次粘贴在一个
．．．．．．．Word
．．．．
文档中
．．．上传（只粘贴部分内容的图片不给分），图片请保持正向、清晰；
1.上传文件命名为“中心-学号-姓名-科目.doc”
2.文件容量大小：不得超过20MB。
提示：未按要求作答题目
．．．．0．分记
．．！
．．．．．，成绩以
．．．及雷同作业
．．．．．．．．的作业
题目如下：
第一组：
计算题（每小题25分，共100分）
1、某企业生产三种产品A1、A
2、A3。每种产品在销售时可能出现销路好(S1)，销路一般(S2)
和销路差(S3)三种状态，每种产品在不同销售状态的获利情况(效益值)如表1所示，请按乐观法则进行决策，选取生产哪种产品最为合适。
表1
2、已知运输问题的运价表和发量和收量如表2所示，请用最小元素法求出运输问题的一组解。
表2
3、下列表3是一个指派问题的效率表(工作时间表)，其中A i 为工作人员(i=1, 2, 3, 4)、B j 为
工作项目(j=1, 2, 3, 4)，请作工作安排，使总的工作时间最小。
表3
4、有一化肥厂用两种原料A,B 生产C,D,E 三种化肥，根据市场调查某地区各种化肥每天最少需求分别为100吨，60吨，130吨。该厂每天可供的原料分别为200吨和240吨。单位成品化肥所耗费的原料及销售利润如下表。问每天应生产多少各类化肥，使该厂利润最大。要求建立线性规划模型，不作具体计算。
B 1 B 2 B 3 B 4 A
1 9 A
2 4 A
3 5
3 5
4 6
B 1 B 2 B 3 B 4
A 1 A 2 A 3 A 4
第二组：
计算题（每小题25分，共100分）
1、下列表是三个不同模型的线性规划单纯形表，请根据单纯形法原理和算法，分别在表中括号中填上适当的数字。
1. 计算该规划的目标函数值
2.确定上表中输入，输出变量。
2、已知一个线性规划原问题如下，请写出对应的对偶模型
max 12
25S x x =+
121212438,0x x x x x x ≤??≤??
+≤??≥?
3、设有某种肥料共6个单位，准备给4块粮田用，其每块粮田施肥数量与增产粮食的关系如下表所示。试求对每块田施多少单位重量的肥料，才能使总的粮食增产最多。
4、求下面问题的对偶规划 极大化
1234
3257z x x x x =--+
C j → 20 15 20 0 0 Ci x B b
x 1 x 2 x 3 x 4 x 5 20 x 1 2 20 x 3 1 0 x 5 3
z j c j －z j
0 -15 0 10 0
1234134123423272+223248
x x x x x x x x x x x ??
??
?+-+≥---≤--+-≥
12340,0,0,x x x x ≥≥≤无非负限制。
第三组：
计算题（每小题25分，共100分）
1.福安商场是个中型的百货商场，它对售货人员的需求经过统计分析如下表所示，为了保证售货人员充分休息，售货人员每周工作五天，休息两天，并要求休息的两天是连续的，问该如何安排售货人员的休息，既满足了工作需要，又使配备的售货人员的人数最少，请列出此
2、某厂生产甲、乙两种产品，这两种产品均需在A 、B 、C 三种不同的设备上加工，每种产品在不同设备上加工所需的工时不同，这些产品销售后所能获得利润以及这三种加工设备因各种条件限制所能使用的有效加工总时数如下表所示：
问：该厂应如何组织生产，即生产多少甲、乙产品使得该厂的总利润为最大
3、用图解法求解
⑴
min z =－3x1+x2 .
?????
????≥≤+≥+≤≤0
8
2125234212
12121
x x x x x x x x ，
4、用单纯形法求解 max z =7x1+12x2 .
??????
?≥≤+≤+≤+0300103200543604921212121x x x x x x x x ，
第四组：
计算题（每小题25分，共100分）
、B 两人分别有10分(1角)、5分、1分的硬币各一枚，双方都不知道的情况下各出一枚，规定和为偶数，A 赢得8所出硬币，和为奇数，8赢得A 所出硬币，试据此列出二人零和对策模型，并说明此游戏对双方是否公平。
2、用图解法求解 max z = 6x1+4x2 .
⑵ ⑶ ⑷ ⑸
⑹、⑺
⑵ ⑶ ⑷ ⑸、⑹
1212212
210870x x x x x x x +≤??+≤??
≤?
?≥?， ⑴
3、用单纯形法求解 max z =70x1+30x2 .
??????
?≥≤+≤+≤+072039450555409321212121x x x x x x x x ，
4.某企业要用三种原材料A 、B 、C 生产出出三种不同规格的产品甲、乙、丙。已知产品的规格要求，产品单价，每天能供应的原材料数量及原材料单价，分别见表1和表2。该企业应如何安排生产，使利润收入为最大
表1
第五组：
计算题（每小题25分，共100分）
1、用标号法求下列网络V 1→V 7的最短路径及路长。
2、某企业生产三种产品A 1、A 2、A 3。每种产品在销售时可能出现销路好(S 1)，销路一般(S 2)和销路差(S 3)三种状态，每种产品在不同销售状态的获利情况(效益值)如表所示，请按乐观法则进行决策，选取生产哪种产品最为合适。
表
3、下列表是一个指派问题的效率表(工作时间表)，其中A i 为工作人员(i=1, 2, 3, 4)、B j 为工作项目(j=1, 2, 3, 4)，请作工作安排，使总的工作时间最小。
表
4、下列表是三个不同模型的线性规划单纯形表，请根据单纯形法原理和算法，分别在表中括号中填上适当的数字。
B 1 B 2 B 3 B 4
A 1
A 2 A 3 A 4
V 1 V 7
V 5 V 6
V 4
V 3
V 2 5
4 3
5 3 1
7 6
1
7
3
1
1. 计算该规划的目标函数值
C j →20 15 20 0 0
Ci x B b x1x2x3x4x5
20 x1 2
20 x3 1
0 x5 3
z j
c j－z j0 -15 0 10 0
2、确定上表中输入，输出变量。
2018年12月英语四级真题（第一套） Part I Writing (30 minutes) Directions: For this part，you are allowed 30 minutes to write a short essay on the challenges of starting a career after graduation. You should write at least 120 words but no more than180 words. PartⅡ Listening Comprehension (25 minutes) 关注公众号“春秋大道”，无偿得到全部英语四六级历年真题（更新至2018年12月）+听力原频 Section A Directions: In this section, you will hear three news reports. At the end of each news report, you will hear two or three questions. Both the news report and then questions will be spoken only once. After you hear a question, you must choose the best answer from the four choices marked A），B), C) and D).Then mark the corresponding letter on Answer Sheet 1with a single line through the centre. Questions 1 and 2 are based on the news report you have just heard. 1.A) Land a space vehicle on the moon in 2019. B) Design a new generation of mobile phones. C) Set up a mobile phone network on the moon. D) Gather data from the noon with a tiny device. 2.A) It is stable. B) It is durable. C) It is inexpensive. D) It is sophisticated.
2018年12月大学英语四级真题完整版（第3套） Part I Writing (30 minutes) Directions: For this part，you are allowed 30 minutes to write a short essay on the challenges of studying abroad. You should write at least 120 words but no more than180 words. PartⅡ Listening Comprehension (25 minutes) Part Ⅲ Reading Comprehension ( 40 minutes) Section A Directions: In this section, there is a passage with ten blanks. You are required to select one word for each blank from a list of choices given in a word bank following the passage. Read the passage through carefully before making your choices. Each choice in the bank is identified by a letter. Please mark the corresponding letter for each item on Answer Sheet 2 with a single line through the centre. You may not use any of the words in the bank more than once． Questions 26 to 35 are based on the following passage. Have you ever used email to apologize to a colleague Delivered a 26 to a subordinate (下属) with a voice-mail message Flown by plane across the country just to deliver important news in person The various communication options at our fingertips today can be good for 27 and productivity---and at the same time very troublesome. With so many ways to communicate, how should a manager choose the one that’s best --- 28 when the message to be delivered is bad or unwelcome news for the recipient We’ve 29 business communication consultants and etiquette (礼仪) experts to come up with the following guidelines for 30 using the alterative ways of delivering difficult messages. First of all, choose how personal you want to be. A face-to-face communication is the most 31 .Other choices, in descending order of personalization, are: a real-time phone call, a voice-mail message, a handwritten note, a typewritten letter, and the most 32 is email. Some of these may change order according to the 33 situation or your own preferences; for example, a handwritten note might seem more personal than voice mail. How do you decide on the best choice for the difficult message you’ve got to deliver “My 34 concern is: How can I soften or civilize this message” says etiquette expert Dana Casperson. “So when
Part I Writing(30 minutes) The Challenges of Living in a Big City 【1】With the development of economy and urbanization, the number of cities is constantly increasing in China.【2】While big cities are attracting more and more people, they also bring many challenges,such as traffic jam and pollution,just to name a few.【3】The first problem that really bothers me is the traffic congestion in the rush hour. I hate waiting for buses and being late.Therefore, I have to get up very early if I have an appointment in the morning.【4】Next is that the large population in a big city makes it【5】so crowded that you can't find a peaceful place unless staying at home. The supermarkets are always crowded, so are the cinemas and parks. parks.【6】Another consequence for such a large population is that it intensifies the inadequacy of quality medical and educational resources, thus decreasing residents' sense of happiness. 【7】As a result, although I am frequently asked whether I like to live in a big city or not, my answer is always no, definitely not, How about you? 话题词汇: unsatisfactory不满意的leisure娱乐opportunity机会 fast pace快节奏 pressure压力 lifestyle生活方式 environment环境 urban城市的 health健康 Part III Reading Comprehension Section A 【词性分析】: 名词: A) ability能力;才能; E) control控制;管制;F) damage伤害;损害; M) sources来源;根源;O) vehicles交通工具,车辆 动词:B) associated与…相关;联系;E) control管理;控制;克制;F) damage损害;对……有不良影响G) described描绘,描述; H equals相当于;比得上;) innovated创新,革新;L) relates相联系;把…系起来;M) sources来自……;找出…的来源;N) undermine逐渐削弱 形容词:D) constant持续不断的;始终如一的 副词:C) consciously有意识地,自觉地; 1) exclusively仅仅,唯独;K) regularly经常;定期地 Millions die early from air pollution each year. Air pollution costs the global economy more than $5 trillion annually in welfare costs, with the most serious 26-damage occurring in the developing world. The figures include a number of costs 27-associated with air pollution. Lost income alone amounts to $225 billion a year. 1.die v. 死亡，熄灭; 凋零n.骰子 2.trillion[?tr?lj?n]n. 万亿; 兆adj.万亿的 3.welfare [?welfe?(r)] n. 福利; 幸福; 繁荣; 安宁 4.alone [??l??n] adj. 单独的; 独一无二的; 独自的adv. 单独地; 独自地; 孤独地; 只，只有; The report includes both indoor and outdoor air pollution. Indoor pollution, which includes 28-sources like home heating and cooking, has remaine d 29-constant over the past several decades despite advances in the area. Levels of outdoor pollution have grown rapidly along with rapid growth in industry and transportation. 5.source [s?rs] n. 根源，本源; 源头，水源; 原因v. 来源; 起源; 寻求来源 6.remain [r??men]n.剩余物，残骸; 残余; 遗迹; 遗体v.留下; 保持;依然; 搁置; 剩余，剩下; 逗留 7.constant [?k?nst?nt] adj. 不断的，持续的; 永恒的，始终如一的; 坚定; 忠实的n.常量; 不变的事物
2018年12月大学英语四级考试真题（第2套） Part I Writing(30minutes) Directions:For this part,you are allowed30minutes to write a short essay on the challenges of studying abroad.You should write at least120words but no more than180words. ___________________________________________________________________________________________________ ___________________________________________________________________________________________________ ___________________________________________________________________________________________________ Part II Listening Comprehension(25minutes) Section A Directions:In this section,you will hear three news reports.At the end of each news report,you will hear two or three questions.Both the news report and the questions will be spoken only once.After you hear a question,you must choose the best answer from the four choices marked A),B),C)and D).Then mark the corresponding letter on Answer Sheet1with a single line through the centre. Questions1and2are based on the news report you have just heard. 1.A)A man was pulled to safety after a building collapse. B)A beam about ten feet long collapsed to the ground. C)A rescue worker got trapped in the basement. D)A deserted100-year-old building caught fire. 2.A)He suffered a fatal injury in an accident. B)He once served in a fire department. C)He was collecting building materials. D)He moved into his neighbor’s old house. Questions3and4are based on the news report you have just heard. 3.A)Improve the maths skills of high school teachers. B)Change British people’s negative view of maths. C)Help British people understand their paychecks. D)Launch a campaign to promote maths teaching. 4.A)Children take maths courses at an earlier age. B)The public sees the value of maths in their life. C)British people know how to do elementary calculations. D)Primary school teachers understand basic maths concepts. Questions5to7are based on the news report you have just heard. 5.A)He owns a fleet of aircraft. B)He is learning to be a pilot. C)He regards his royal duties as a burden. D)He held a part-time job for over20years. 6.A)He can demonstrate his superior piloting skills. B)He can change his focus of attention and relax. C)He can show his difference from other royalty. D)He can come into closer contact with his people. 7.A)They enjoyed his company.
2018年12月大学英语四级真题完整版（第1套） Part I Writing (30 minutes) Directions: For this part，you are allowed 30 minutes to write a short essay on the challenges of starting a career after graduation.You should write at least 120 words but no more than180 words. PartⅡ Listening Comprehension (25 minutes) Section A Directions: In this section, you will hear three news reports. At the end of each news report, you will hear two or three questions. Both the news report and then questions will be spoken only once. After you hear a question, you must choose the best answer from the four choices marked A），B), C) and D).Then mark the corresponding letter on Answer Sheet 1with a single line through the centre. Questions 1 and 2 are based on the news report you have just heard. A) A man was pulled to safety after a building collapse. B) A beam about ten feet long collapsed to the ground C) A rescue worker got trapped in the basement D) A deserted 100-year-old building caught fire 2. A)He suffered a fatal injury in an accident. B) He once served in a fire department. C) He was collecting building materials. D) He moved into his neighbor's old house. Questions 3 and 4 are based on the news report you have just heard. 3. A) Improve the maths skills of high school teachers. B) Change British people’s negative view of maths C) Help British people understand their paychecks. D) Launch a campaign to promote maths teaching. 4. A) Children take maths courses at an earlier age. B) The public sees the value of maths in their life. C) British people know how to do elementary calculations D) Primary school teachers understand basic maths concepts. Questions 5 and 6 are based on the news report you have just heard. 5. A) He owns a fleet of aircraft. B) He is learning to be a pilot.
2018年12月英语四级考试参考答案（全三套） 第一套 听力原文 News 1 A device that weighs less than one kilogram is part of a mission that will allow scientists to deliver fourth generation or 4G mobile coverage to the moon in 2019. If successful, the tiny device will provide the moon with its first ever mobile phone network. The lunar network will support high definition streaming of video and data between the moon and earth. The network is part of a mission to the moon. This is a project with the goal of landing the first privately paid for mission to the moon. The 4G mission is set to launch from Cape Canaveral in the United States on a space X Falcon 9 rocket in 2019. Mission to the moon intends to establish and test the first elements of a communications network on the moon. The scientists working on the project opted to build a 4G rather than a fifth generation or 5G network. This is because fifth generation networks are still in testing and trial phases. This means that a 5G network may not yet be stable enough to work on the moon’s surface. Question 1: What are scientists planning to do? Question 2: Why did scientists choose to set up a 4G network in their mission? News 2 It’s responded to a fire Wednesday night at an abandoned mall in Heywood. The fire was reported at 9:26 pm at an old shopping center on Michigan Avenue near St. Mary’s Church. Six fire engines, two trucks and two chiefs responded to the scene. Crews had the fire under control in about 45 minutes and managed to contain the fire to its point of origin. There were some people inside the building when the fire broke out but there were no reports of any injuries. Fire investigators have responded to the scene but have not yet determined the cause of the fire. Firefighters will remain on the scene until later this morning to ensure that the fire
运筹学 要求： 一、独立完成，下面已将五组题目列出，请按照学院平台指定 ．．的做题组数作答， 每人只 ．．．．，满分100分； ．．．答．一组题目 ．．．．，多答无效 平台查看做题组数操作：学生登录学院平台→系统登录→学生登录→课程考试→离线考核→离线考核课程查看→做题组数，显示的数字为此次离线考核所应做哪一组题的标识； 例如：“做题组数”标为1，代表学生应作答“第一组”试题； 二、答题步骤： 1.使用A4纸打印学院指定答题纸（答题纸请详见附件）； 2.在答题纸上使用黑色水笔 ．．作答；答题纸上全部信息要求手 ．．．．按题目要求手写 写，包括学号、姓名等基本信息和答题内容，请写明题型、题号； 三、提交方式：请将作答完成后的整页答题纸以图片形式依次粘贴在一个 ．．．．．．．Word ．．．． 文档中 ．．．上传（只粘贴部分内容的图片不给分），图片请保持正向、清晰； 1.上传文件命名为“中心-学号-姓名-科目.doc” 2.文件容量大小：不得超过20MB。 提示：未按要求作答题目 ．．．．0．分记 ．．！ ．．．及雷同作业 ．．．．．，成绩以 ．．．．．．．．的作业 第三组： 计算题（每小题25分，共100分） 1.福安商场是个中型的百货商场，它对售货人员的需求经过统计分析如下表所示，为了保证售货人员充分休息，售货人员每周工作五天，休息两天，并要求休息的两天是连续的，问该如何安排售货人员的休息，既满足了工作需要，又使配备的售货人员的人数最少，请列出此
解：通过分析确定决策变量：设星期一至星期天开始休息的人数分别为x1,x2,x3,x4,x5,x6,x7;则可以确定目标函数：Min = x1 +x2+x3+x4+x5+x6+x7 通过上表可以确定约束条件有： x1+x2+x3+x4+x5 >=28 x2+x3+x4+x5+x6>=15 x3+x4+x5+x6+x7>=24 x4+x5+x6+x7+x1>=25 x5+x6+x7+x1+x2>=19 x6+x7+x1+x2+x3 >=31 x7+x1+x2+x3+x4>=28 x1,x2,x3,x4,x5,x6,x7>=0 因此，可以建立下列数学模型： Min = x1 +x2+x3+x4+x5+x6+x7 x1+x2+x3+x4+x5 >=28 x2+x3+x4+x5+x6>=15 x3+x4+x5+x6+x7>=24 x4+x5+x6+x7+x1>=25 x5+x6+x7+x1+x2>=19 x6+x7+x1+x2+x3 >=31 x7+x1+x2+x3+x4>=28 x1,x2,x3,x4,x5,x6,x7>=0
Part I. Writing (30 minutes) Directions: For this part, you are allowed 30 minutes to write a short essay on the challenges of living in a big city. You should write at least 120 words but no more than 180 words. Part II. Listening Comprehension (30 minutes) Section A News Report Directions：In this section，you will hear three news reports。At the end of each news report，you will hear two or three questions。Both the news report and the questions will be spoken only once。After you hear a question，you must choose the best answer from the four choices marked A），B），C）and D）。Then mark the corresponding letter on Answer Sheet 1 with a single line through the centre。 Questions 1 and 2 are based on the news report you have just heard. 1. A) Land a space vehicle on the moon in 2019. B) Design a new generation of mobile phones. C) Set up a mobile phone network on the moon. D) Gather data from the moon with a tiny device. 2. A) It is stable. B) It is durable. C) It is inexpensive. D) It is sophisticated. Questions 3 and 4 are based on the news report you have just heard. 3. A) It lasted more than six hours. B) No injuries were yet reported. C) Nobody was in the building when it broke out. D) It had burned for 45 minutes by the time firefighters arrived. 4. A) Recruit and train more firefighters. B) Pull down the deserted shopping mall. C) Turn the shopping mall into an amusement park. D) Find money to renovate the local neighborhood. Questions 5 to 7 are based on the news report you have just heard. 5. A) Shrinking potato farming. B) Heavy reliance on import. C) Widespread plant disease. D) Insufficient potato supply. 6. A) It intends to keep its traditional diet. B) It wants to expand its own farming. C) It is afraid of the spread of disease. D) It is worried about unfair competition. 7. A) Global warming. B) Ever-rising prices.
2018 年 12 月大学英语四级阅读真题 选词填空 Part Ⅲ Reading Comprehension ( 40 minutes) Section A Directions: In this section, there is a passage with ten blanks. You are required to select one word for each blank from a list of choices given in a word bank following the passage. Read the passage through carefully before making your choices. Each choice in the bank is identified by a letter. Please mark the corresponding letter for each item on Answer Sheet 2 with a single line through the centre. You may not use any of the words in the bank more than once. Questions 26 to 35 are based on the following passage. Millions die early from air pollution each year. Air pollution costs the global economy more than $5 trillion annually in welfare costs, with the most serious 26 occurring in the developing world. The figures include a number of costs 27 with air pollution. Lost income alone amounts to $225 billion a year. The report includes both indoor and outdoor air pollution. Indoor pollution, which includes 28 like home heating and cooking, has remained 29 over the past several decades despite
审计学 要求： 一、独立完成，下面已将五组题目列出，请按照学院平台指定 ．．的做题组数作答， 每人只 ．．．．，满分100分； ．．．．，多答无效 ．．．答．一组题目 平台查看做题组数操作：学生登录学院平台→系统登录→学生登录→课程考试→离线考核→离线考核课程查看→做题组数，显示的数字为此次离线考核所应做哪一组题的标识； 例如：“做题组数”标为1，代表学生应作答“第一组”试题； 二、答题步骤： 1.使用A4纸打印学院指定答题纸（答题纸请详见附件）； 2.在答题纸上使用黑色水笔 ．．．．按题目要求手写 ．．作答；答题纸上全部信息要求手写，包括学号、姓名等基本信息和答题内容，请写明题型、题号； 三、提交方式：请将作答完成后的整页答题纸以图片形式依次粘贴在一个 ．．．． ．．．．．．．Word 文档中 ．．．上传（只粘贴部分内容的图片不给分），图片请保持正向、清晰； 1.上传文件命名为“中心-学号-姓名-科目.doc” 2.文件容量大小：不得超过20MB。 提示：未按要求作答题目 ．．．．0．分记 ．．．．．，成绩以 ．．！ ．．．．．．．．的作业 ．．．及雷同作业 题目如下： 第一组： 一、问答题（30分） A注册会计师接受甲公司的委托，对甲公司管理层编制的下属子公司乙公司IT系统运行有效性的评价报告（管理层的认定）进行鉴证（再认定）。甲公司拟将该评价报告提交给其他预期使用者。 要求：（1）指出该项鉴证业务属于下表中何种业务类型，直接在答题卷表格中相应位置打“√”。 第一问：答案
（2）请指出该项鉴证业务的责任方，并简要说明甲公司管理层、乙公司管理层和A注册会计师各自的责任。 （3）在评价乙公司IT系统运行有效性时，甲公司使用的是其自行制定的标准。请简要说明A注册会计师应当从哪些方面评价标准的适当性。 （4）在承接业务后，如果发现标准不适当，A注册会计师应当出具何种类型的鉴证报告？ 二、业务题（30分） 某注册会计师正在对甲公司的应付帐款和银行存款项目进行审计，根据需要，决定对两个项目实施函证，有关资料如下： “应付帐款”有关资料 供应商年末余额（元）本年进货总额（元） A公司 12650 42100 B公司 0 225800 C公司 6500 7500 D公司 36000 83863 “银行存款”有关资料 开户行及帐号银行存款余额（元） E中国工商银行＊＊＊1 8036000 F中国农业银行＊＊＊2 5130 G中国建设银行＊＊＊3 587500 H民生银行＊＊＊＊＊4 0 试问：（1）若决定对二家供应商进行函证，应选择哪二家？为什么？函证的内容及方式是什么？
钢结构设计原理 要求： 一、独立完成，下面已将五组题目列出，请按照学院平台指定 ．．的做题组数作答， 每人只 ．．．．，满分100分； ．．．．，多答无效 ．．．答．一组题目 平台查看做题组数操作：学生登录学院平台→系统登录→学生登录→课程考试→离线考核→离线考核课程查看→做题组数，显示的数字为此次离线考核所应做哪一组题的标识； 例如：“做题组数”标为1，代表学生应作答“第一组”试题； 二、答题步骤： 1.使用A4纸打印学院指定答题纸（答题纸请详见附件）； 2.在答题纸上使用黑色水笔 ．．．．按题目要求手写 ．．作答；答题纸上全部信息要求手写，包括学号、姓名等基本信息和答题内容，请写明题型、题号； 三、提交方式：请将作答完成后的整页答题纸以图片形式依次粘贴在一个 ．．．． ．．．．．．．Word 文档中 ．．．上传（只粘贴部分内容的图片不给分），图片请保持正向、清晰； 1.上传文件命名为“中心-学号-姓名-科目.doc” 2.文件容量大小：不得超过20MB。 提示：未按要求作答题目 ．．．．0．分记 ．．．．．，成绩以 ．．！ ．．．．．．．．的作业 ．．．及雷同作业 第五组： 一、简答题（每小题25分，共50分） 1、计算格构式轴心受压柱绕虚轴的稳定时为什么采用换算长细比？ 答：格构式轴心受压构件，当绕虚轴失稳时，因肢件之间并不是连续的板而只是每隔一定距离用缀条或缀板联系起来，构件的剪切变形较大，剪力造成的附加影响不能忽略。因此，采用换算长细比来考虑缀材剪切变形对格构式轴心受压构什绕虚轴的稳定承载力的影响。 2、何为钢材的疲劳断裂？如何进行常幅疲劳计算？ 答：钢结构的疲劳断裂是裂纹在连续重复荷载作用下不断扩展以至断裂的脆性破坏，塑性变形极小，破坏前没有明显的破坏预兆，危险性较大。出现疲劳断
2018年12月大学英语四级真题及答案 第一部分写作 2018年12月大学英语四级考试写作真题(第1套) 2018年12月英语四级真题写作范文(出国留学的挑战) 【作文一参考范文】 It is well known that due to the booming economy and increasing family income, studying abroad has become an increasingly popular choice for students. Although studying abroad is often praised by people for its advantages, there are still some disadvantages to be noticed. First of all, to study abroad is expensive. Specifically speaking, those involved have to spend a large amount of money on tuition and living expenses, which is not affordable for everyone. In addition, to study abroad is a great challenge for those students who lack the ability of living independently. If they can not take good care of themselves there, their academic performance will be affected to a large extent. Last but not least, to study abroad may exercise a negative influence on students’ mentality. As we all know, to study abroad equals to stay away from family and friends for a long time, which is likely to produce some psychological problems for those students, such as being solitary and gloomy. From what has been mentioned above, we can easily come to the conclusion that the disadvantages of studying abroad can not be neglected. What’s more, those students who are planning to study abroad should make enough preparations for these problems mentioned above. Only in this way, can they have a fruitful and successful study life abroad. 【参考译文】 众所周知，随着经济的蓬勃发展和家庭收入的增加，出国留学已经成为越来越受学生欢迎的选择。虽然出国留学的优点经常被人们称赞，但仍有一些缺点需要注意。 首先，出国留学的费用是昂贵的。具体来说，这些人不得不花费一大笔钱在学费和生活费上，而这并不是每个人都负担得起的。此外，对于那些缺乏独立生活能力的学生来说，出国留学是一个巨大的挑战。如果他们不能照顾好自己，他们的学习成绩将在很大程度上受到影响。最后但并非最不重要，出国留学可能会对学生的心理产生负面影响。众所周知，出国留学等于长时间远离家人和朋友，这很可能使留学生产生一些心理问题，如孤僻和沮丧。 综上所述，我们不难得出以下结论：出国留学的缺点是不能忽视的。更重要的是，那些计划出国留学的学生应该为解决这些问题做好充足的准备。只有这样，他们才能有一个丰富多彩且成功的留学生活。 2018年12月英语四级真题作文:大城市生活的挑战 【作文二参考范文】 Recently the phenomenon of living in a big city has been brought into focus. With the population of dwelling in a big city increasing dramatically for its convenient infrastructure and higher wage level, the challenges have also aroused more and more concerns among the society. First of all, the most obvious problem is the issue of traffic. In a big cities, traffic jam is quite common everywhere, especially in the rush time. Consequently, a large number of people have to spend much time in commuting. In the second place, with the growth of cars and buses in big cities, air pollution has become another disadvantage, which may do harm to the health of people. Last but not least, people living in a big city tend to endure more pressure of work and life, which may, directly or indirectly, influence their mental health. So what will be the possible tendency of this situation in the following decades? From my