东大19春学期《计算机辅助设计基础》在线作业3

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东大19春学期《计算机辅助数控编程》在线作业3参考答案

第一种情况，对于双方当事人都是既知道有违反婚姻生效的法定事由，又对此事由有过错的，适用现行的规定，即双方协商，协商不成的，由法院裁判。第二种情况，对于仅知道有违反婚姻生效事由但没有过错的当事人，在财产分配过程中应当少分，而不论是否属于弱国一方。因为这种情形下，当事人对社会公共利益和法律秩序的挑衅太严重，应当予以更加不利的法律后果。第三种情况，对于不知道存在违反婚姻生效法定事由但是有过错的当事人，境如当事人婚前不知自己患有禁止结婚的疾病而后导致婚姻可撤销，可以适用离婚时财产分割的相关规定。第四种情况，对于既不知道存在违反婚姻生效要件存在，对此又没有过错责任的当事人应当适用离婚时的财产分割规定。因为以上情形中，当事人对社会公益和法律秩序的破坏很小，甚至是无辜的，应当适用更为有利的法律制度。但是需要注意的时，当事人不知的状态需要一直持续到婚姻被确认无效或者被撤销，否者将构化为第一种或者第二种情况。最后，对于子女抚养在题一律适用与离婚时一样的对子女保护的相关规定。
A.NC代码
B.加工轨迹
C.刀具
D.机床
正确答案:B
12.图标按钮的功能是创建。
A.旋转体
B.块体
C.锥体
D.球体
正确答案:A
13.三维动态切削仿真主要用来解决加工过程中、实际加工环境内、间的干涉碰撞问题和运动关系。
A.生产系统
B.工艺系统
C.设计过程
D.调度过程
正确答案:B
14.图标按钮的功能是。
首先，笔者认为应当调整现行婚姻无效与可撤销规定的溯及力在题。溯及力涉及到对之前婚姻事实的法律认可状况。如果溯及既往，那么婚姻关系自成立起无效，从而导致因夫妻身份关系产生的其他一切行为也将陷入纠纷，对于与之有交易的第三人来讲将面临不可预测的法律法风险，不利于交易安全。笔者认为应当根据无效婚姻与可撤销婚姻中不同法定情形的违法程度区分为无效婚姻和可撤销婚姻的溯及力。在笔者对于无效婚姻法定情形重构之后，只剩下重婚、近亲婚姻以及未满十六周岁未成年人婚姻三种，本以为可以完全适用的无效婚姻被确认无效后自始无效的规定，但是在引入责任要素之后，笔者发现其中可能存在无辜方的情况，如重婚情形中被重婚的一方不知对方已有配偶，在婚姻被宣告无效之后，被重婚者依然与造成婚姻无效的一方当事人共同承担婚姻自始无效一样的结果，这样的规定对被重婚者不公平，也不利于保护子女的利益。笔者认为应参虑双方当事人的责任区分不同的溯及力，由造成婚姻无效的一方承担婚姻自始无效的后果，无辜一方则自法院宣告无效之日起婚姻开始无效。实际生活中造成婚姻无效的责任人可能是当事人一方，也可能是双方，可统一适用上无规则，笔者认为更加公平。笔者对可撤销婚姻的法定情形重构之后扩充了未达法定婚龄的婚姻、患禁婚疾病的婚姻、欺诈的婚姻与重大误解的婚姻。笔者认为此部分也不可以完全重构为“婚姻被撤销的，自撤销之日起生效”。因为尽管重构后的可撤销婚姻制度所保护的个人私益要件，但是其中当事人还是有过错方与无辜方的区分，适用同种法律后果依然不公平，应当根据造成婚姻无效的责任有无、大小区别对待，重构为“对婚姻被撤销有责任的，适用婚姻自始无效规定，无责任的适用撤销之日起无效。”

东大-21春学期《计算机辅助设计》在线平时作业1-答案资料

[东北大学]21春学期《计算机辅助设计》在线平时作业1
提示：本套试卷是课程辅导学习资料，仅做课程学习参考使用！！
一、单选题 (共 10 道试题,共 50 分)
1.在执行“延伸”命令的过程中，需要用户选择( )种对象
[A.]1
[B.]2
[C.]3
[D.]4
[提问：对上述试题分析作答，并选择您认为正确的进行选择]
参考答案:B
2.在CAD中内部块创建命令的快捷键是( )
[A.]a
[B.]b
[C.]c
[D.]d
[提问：对上述试题分析作答，并选择您认为正确的进行选择]
参考答案:B
3.在CAD中块插入命令的快捷键是( )
[A.]r
[B.]c
[C.]i
[D.]j
[提问：对上述试题分析作答，并选择您认为正确的进行选择]
参考答案:C
4.在CAD中以下有关图层锁定的描述，错误的是( )
[A.]在锁定图层上的对象仍然可见
[B.]在锁定图层上的对象不能打印
[C.]在锁定图层上的对象不能被编辑
[D.]锁定图层可以防止对图形的意外修改
[提问：对上述试题分析作答，并选择您认为正确的进行选择]
参考答案:B
5.在CAD中绘制圆弧快捷键是( )
[A.]tr
[B.]a
[C.]rec
[D.]pl
[提问：对上述试题分析作答，并选择您认为正确的进行选择]
参考答案:B。

东大19春学期《常用电器控制技术(含PLC)》在线作业3【标准答案】

(判断题)1: 对于一些超高压、大容量的巨型变压器，为了减少制造及运输困难，常采用三相心式变压器。

A: 错误B: 正确正确答案:(判断题)2:    HH系列铁壳开关合闸后，开关盖不能自由打开。

             &n bsp;             （）A: 错误B: 正确正确答案:(判断题)3: 用户存储器使用EPROM（只读存储器），用于存放系统程序。

A: 错误B: 正确正确答案:(判断题)4:   HH系列铁壳开关开关盖开启后，可以自由合闸。

             &n bsp;             （）A: 错误B: 正确正确答案:(判断题)5:  电路图不能与接线图或接线表混合绘制A: 错误B: 正确正确答案:(判断题)6: 真空断路器的核心部件是真空灭弧室。

14秋学期东大《计算机辅助设计基础》在线作业

14秋学期东大《计算机辅助设计基础》在线作业14秋学期《计算机辅助设计基础》在线作业1试卷总分：100 测试时间：-- 试卷得分：100单选题判断题包括本科在内的各科复习资料及详细解析，可以联系屏幕右上的“文档贡献者”一、单选题（共5 道试题，共25 分。

）得分：25V 1. Cohen-Sutherland算法称为？A. 编码裁剪算法B. 矢量裁剪算法C. 中点分割裁剪算法D. 以上都不是满分：5 分得分：52. 在C/S的哪一种分布模式中，客户信息被多个服务器接受，但不要求返回响应？A. 任务承包模式B. 单客户－多服务器模式C. 广播模式D. 链式服务器模式满分：5 分得分：53. 机械设计过程一般经历三个阶段，下面哪一个不属于？A. 概念设计B. 完善设计C. 初步设计D. 详细设计满分：5 分得分：54. 下面哪个坐标系采用无量纲的单位？A. 世界坐标系B. 观察坐标系C. 规格化设备坐标系D. 设备坐标系5. AutoCAD中，用编辑命令一次可去掉多条长出某直线的线条。

A. ERASEB. TRIMC. BREAKD. UNDO满分：5 分得分：5二、判断题（共15 道试题，共75 分。

）得分：75V 1. 工程工作站的概念萌生于20世纪60年代。

A. 错误B. 正确满分：5 分得分：52. 具有图形参数化功能的CAD系统最根本的改进是它能够记录和识别几何图形的拓扑关系和几何约束关系。

A. 错误B. 正确满分：5 分得分：53. CAD在早期是英文Computer Aided Design（计算机辅助设计）的缩写。

A. 错误B. 正确满分：5 分得分：54. 1992年，我国以“甩掉图板”为突破口，启动了CAD应用工程。

A. 错误B. 正确满分：5 分得分：55. 几何造型软件可以在工作站上运行，不可以在微机上运行。

A. 错误B. 正确满分：5 分得分：56. 表格文件具有数据结构化与逻辑性强的特点，一般采用整体打包管理。

东大19春学期《计算机网络》在线作业3【标准答案】

(单选题)1: 网卡工作在OSI七层模型中的（）层。

A: 物理层B: 数据链路层C: 网络层D: 运输层正确答案:(单选题)2: 接收窗口和发送窗口都等于1的协议是（）。

A: 停止等待协议B: 连续ARQ协议C: PPP协议D: 选择重传ARQ协议正确答案:(单选题)3: 无论是SLIP还是PPP协议都是（）协议。

A: 物理层B: 数据链路层C: 网络层D: 传输层正确答案:(单选题)4: 在一个 Ethernet 中，有 A、B、C、D 四台主机，如果 A 向 B 发送数据，那么（）。

A: 只有B可以接收到数据B: 数据能够瞬间到达BC: 数据传输存在延迟D: 其它主机也可以同时发送数据正确答案:(单选题)5: 网络中用集线器或交换机连接各计算机的这种拓扑结构属于（）。

A: 总线结构B: 星型结构C: 环形结构D: 网状结构正确答案:(单选题)6: 普通的长途电话采用的交换方式为（）。

A: 分组交换B: 电路交换C: 报文交换D: 信元交换正确答案:(单选题)7: 对等层实体之间采用（）进行通信。

A: 服务B: 连接C: 协议D: 信令正确答案:(单选题)8: 检查网络连通性的应用程序是：（）。

A: PINGB: ARPC: BINDD: DNS正确答案:(单选题)9: TCP使用（）进行流量控制。

A: 三次握手B: 自动重发机制C: 窗口控制机制D: 端口机制正确答案:(单选题)10: 下列哪一种说法是正确的（）。

A: 集线器具有对信号整形的功能B: 集线器具有信息过滤功能C: 集线器具有路径选择功能D: 集线器具有交换功能正确答案:(单选题)11: 局域网参考模型一般不包括（）。

A: 网络层B: 物理层C: 数据链路层D: 介质访问控制层正确答案:(单选题)12: 各种网络在物理层互连时要求（）。

A: 数据传输率和链路协议都相同B: 数据传输率相同，链路协议可不相同C: 数据传输率可不同，链路协议相同D: 数据传输率和链路协议都可不同正确答案:(单选题)13: 以太网交换机在网络帧碎片较多时，工作在（）状态下效率最高。

东大19春学期《大学英语(一)》在线作业3【标准答案】

(µ¥Ñ¡Ìâ)1: If you want to learn English well, don’t forget intensive reading and _____ reading.A: extendedB: extensiveC: wideD: externalÕýÈ·´ð°¸:(µ¥Ñ¡Ìâ)2: He       excited at the good newsA: lookB: appearsC: disappearD: feelÕýÈ·´ð°¸:(µ¥Ñ¡Ìâ)3:When I got to his home, he ____ ____ for an hour.A: had leftB: leftC: had been awayD: has been awayÕýÈ·´ð°¸:(µ¥Ñ¡Ìâ)4: He left the spot immediately, afraid of being ____ in the car accident.A: connectedB: takenC: seatedD: involvedÕýÈ·´ð°¸:(µ¥Ñ¡Ìâ)5: Will there be a strong wind ____ the north ______ the Huanghe River ?A:  to... ofB: to... offC: at... ofD: on… offÕýÈ·´ð°¸:(µ¥Ñ¡Ìâ)6: Scientific discoveries are often applied_____ industrial production methods.A: for B: with C: to D: onÕýÈ·´ð°¸:(µ¥Ñ¡Ìâ)7: I asked the bank for a _____.A: loafB: loadC: loanD: loamÕýÈ·´ð°¸:(µ¥Ñ¡Ìâ)8: The teacher required that all the assignments _____finished before this weekend.A: would beB: wereC: beD: are toÕýÈ·´ð°¸:(µ¥Ñ¡Ìâ)9:Everyone except Tom and John ______  there when the meeting began.A: isB: wasC: areD: wereÕýÈ·´ð°¸:(µ¥Ñ¡Ìâ)10: A good habit can make our mental health in      with physical health.A: concernB: connectionC: compareD: tuneÕýÈ·´ð°¸:(µ¥Ñ¡Ìâ)11:  May she _______ with you?A: comeB: comesC: comingD: cameÕýÈ·´ð°¸:(µ¥Ñ¡Ìâ)12: Which is the best approach _____ the tunnel?A: toB: withC: besidesD: towardsÕýÈ·´ð°¸:(µ¥Ñ¡Ìâ)13:He could_____ neither French or German,&n bsp;so I____ with him in English.A: speak, talkedB: talk, toldC: say, spokeD: tell, talkedÕýÈ·´ð°¸:(µ¥Ñ¡Ìâ)14:Don’t spend _______ time on compute r games.A: too muchB: much tooC: too manyD: many tooÕýÈ·´ð°¸:(µ¥Ñ¡Ìâ)15: Many girls like __________ skirts in summer.A: wearingB: dressingC: inD: putting onÕýÈ·´ð°¸:(µ¥Ñ¡Ìâ)16:Look! Lily with her sister _________&nbsp ;a kite on the playground.A: is flyingB: are flyingC: flyingD: flyÕýÈ·´ð°¸:(µ¥Ñ¡Ìâ)17: My home is about ________ from my school.A: 15 minutesB: minute's rideC: 20 minutes by bikeD: 15- minute's on foot.ÕýÈ·´ð°¸:(µ¥Ñ¡Ìâ)18:The policeman stopped ________, but he&nb sp;_______ no sound.A: hearing,heardB: listening,listenedC: to listen,heardD: listening to,listened toÕýÈ·´ð°¸:(µ¥Ñ¡Ìâ)19:  He walked ________ fast for us ________catch up with. A: so, thatB: such, thatC: enough, toD: too,toÕýÈ·´ð°¸:(µ¥Ñ¡Ìâ)20:  He failed the exam because he didn’t have      time(×ã¹»µÄÊ±¼ä) to prepare.A: rightB: spareC: adequateD: ownÕýÈ·´ð°¸:(µ¥Ñ¡Ìâ)21: The evidence found in this search is always incomplete and _____, it is also frequently partial.A: scatter  B: scattered C: scattering D:  scattered toÕýÈ·´ð°¸:(µ¥Ñ¡Ìâ)22: The museum has some new _____from India.A: exhibit B: exhibition C: exhibits D: exhibitionsÕýÈ·´ð°¸:(µ¥Ñ¡Ìâ)23: The organization performed an important _____ in protectingthe rights of children.A: functionB: fictionC: fractionD: frictionÕýÈ·´ð°¸:(µ¥Ñ¡Ìâ)24: ---He can swim. ---_______ .A: So I canB: So can IC: I so canD: Can I soÕýÈ·´ð°¸:(µ¥Ñ¡Ìâ)25:  He ________ living in the country to the city. A: likesB: prefersC: enjoysD: lovesÕýÈ·´ð°¸:(µ¥Ñ¡Ìâ)26: What kind of music is your_____?A: favorableB: favoriteC: favorD: fateÕýÈ·´ð°¸:(µ¥Ñ¡Ìâ)27: --Must we finish our homework now?--No, you ______. You _______ finish it after school.A: needn't , mayB: mustn't , mayC: can't , canD:  needn't , mustÕýÈ·´ð°¸:(µ¥Ñ¡Ìâ)28: -- You seem to like sweets. --________ . I buy sweets every week.¡¡¡¡ A: So do IB: So I doC: So am ID: So I amÕýÈ·´ð°¸:(µ¥Ñ¡Ìâ)29: It is not _____to quarrel with your boss.A: worthyB: worthC: valueD: valuableÕýÈ·´ð°¸:(µ¥Ñ¡Ìâ)30: --Would you give me some water?  --____________.A: Yes, I wouldB: CertainlyC: No, thanksD: Yes,pleaseÕýÈ·´ð°¸:(ÔÄ¶ÁÀí½â)31:     He was struggling to tie his shoes.I was struggling with whether I should help him.    I did, and he was grateful.“Thank you,” he said.“I’m glad I could help. I just thought it would be easier for me to reach,” I said.    He was a disabled man, and forced to look down most of the time. His arms and legs were twisted terribly, and he couldn’t do what the rest of us would consider easy tasks. He always managed to look up to see how you reacted to his words, however. He had a big smile, making me feel comfortable.     I was still on my knees by his wheelchair.“ Nice shoes,” he said.“Thanks. No one ever complimented me on them before,” I said.“No one has the same view of the world as I do,” he replied.“Tell me about the world as you see it,” I said smiling.“Most people can see if someone is comfortable with them or not in their eyes. I see it in their feet.” he said. “If people keep moving their feet, I just let them go, because I know they’re impatient with me. I don’t want to make people uncomfortable.“What about me? I asked.“I could see your compassion. And then you came down to my level. I was the one who was nervous.” he said. “I don’t normally have someone look me in the eye.”“They don’t know what they’re missing,” I told him.“My old face is nothing to brag about.” he said.“But that smile is so big.”    Yes, and it’s not only a big smile but an attitude.ÕýÈ·´ð°¸:(ÔÄ¶ÁÀí½â)32:     My summer hols wr CWOT. B4. we usd 2 go 2 NY 2C my bro, his GF £¦ thr 3 : -@ kids FTF. ILNY, its gr8.    Can you understand this sentence? If you can’t, don't feel too bad: neither could the middle school teacher in England who received this as homework. This is Netspeak: the language of computerized communication found on Internet or cellphones. To newcomers, it ran like a completely foreign language. So, what is the "translation" of the sentence above? My summer holidays were a complete waste of time. Before, we used to go to New York to see my brother, his girlfriend, and their three screaming kids face to face.I love New York; it’s great.    Schoolteachers and parents say this new form of writing is harming the English language. Increasing spelling and grammatical mistakes can be seen in students' writing. They fear the language could become corrupted (ÃæÄ¿È«·ÇµÄ).    Everyone should just relax, say linguists (ÓïÑÔÑ§¼Ò). They believe Netspeak is in fact more of a good thing. David Crystal, from the University of Wales, argues that Netspeak and Internet create a new language use and the almost lost art of diary writing has been picked up again. Geoffrey Nunberg, from Stanford University, agrees. "People get better at writing by writing," he says, “Kids who are now doing text messaging, e-mail, and instant messages will write at least as well as, and possibly better than their parents."    Linguist James Milroy says, for centuries, it is believed without exception that young people are harming the language. And you can bet your bottom dollar that when today's teenagers become tomorrow's parents, they too will think this way, Milroy argues that languages do not and cannot become "corrupted"; they simply change to meet the new needs.    However, Netspeakers do agree that it is important to teach young people how to speak and write Standard English. Cynthia McVey says, "I can understand Netspeak worries teachers and it's important that they get across to their pupils that text messaging is for fun, but that learning to write proper English is a must for their future.”    Perhaps we should give teenagers a little more trust anyway. Erin, age 12, says, "I wouldn't use text language in my homework. Texting is just for fun."ÕýÈ·´ð°¸:(ÔÄ¶ÁÀí½â)33:     What might the future be like? Here are some predictions: things to come, things to go.     The Spring Festival, the most important Chinese holiday when everyone returns home, has caused headaches for millions of Chinese. More than 2 billion people travel at the same time, making getting travel ticketsand the journey difficult. But in 28 years, Spring Festival travel may not be a problem at all. China plans to build more than 120,000 kilometers of railway and a fast transportation network that will serve 90% of the population by 2020. And because most of China will be cities, people will not have to go to other places to find a job, so it will no longer be a problem.    Newspaper will come to an end in 2043. In the future, digital newspapers will be sent to personal web tools through Internet. Readers can discuss topics with journalists and editors. Information will move faster.     Oil is running out faster than expected. But scientists have found something else for oil as fuel. Coal, natural gas, solar power, nuclear power and even water can take the place of oil as sources of energy.     Schools will go electronic. Computers will be important and popular among the students. Everything will be in the computer and students will not need to bring books to school. They will find information on the Internet. A computer will be the students’ library, schoolbag and connection to the outside world. There will be robot teachers, they will check homework on computers and communicate with the students’ parents through e-mail. And school buses will be like spaceships, comfortable and safe.ÕýÈ·´ð°¸:(ÔÄ¶ÁÀí½â)34:     More and more people like bicycling and it is no surprise. It is fun, healthy and good for the environment. Maybe that’s why there are 1.4 billion bicycles and only 400 million cars on roads worldwide today. Bikes can take you almost anywhere, and there is no oil cost!    Get on a bicycle and ride around your neighborhood. You may discover something new all around you. Stopping and getting off a bike is easier than stopping and getting out of your car. You can bike to work and benefit (ÊÜÒæ) from the enjoyable exercise without polluting the environment. You don’t even have to ride all the way.    Folding (ÕÛµþ) bikes work well for people who ride the train. Just fold the bike and take it with you. You can do the same on an airplane. A folding bike can be packed in a suitcase. You can also take a common bike with you when you fly. But be sure to look for information by getting on airline websites. Not all airlines are bicycle-friendly to travelers.Health Benefits of Bicycling:? It helps to prevent heart diseases.? Bicycling helps to control your weight.     A 15-minute bike ride to and from work three times a week burns off five kilos of fat in a year.? Bicycling can improve your mood.      Exercise like bicycling has been shown to make people feel better, more relaxed andself-confident.? Bicycling is healthier than driving.ÕýÈ·´ð°¸:(µ¥Ñ¡Ìâ)1: If you want to learn English well, don’t forget intensive reading and _____ reading.A: extendedB: extensiveC: wideD: externalÕýÈ·´ð°¸:(µ¥Ñ¡Ìâ)2: He       excited at the good newsA: lookB: appearsC: disappearD: feelÕýÈ·´ð°¸:(µ¥Ñ¡Ìâ)3:When I got to his home, he ____ ____ for an hour.A: had leftB: leftC: had been awayD: has been awayÕýÈ·´ð°¸:(µ¥Ñ¡Ìâ)4: He left the spot immediately, afraid of being ____ in the car accident.A: connectedB: takenC: seatedD: involvedÕýÈ·´ð°¸:(µ¥Ñ¡Ìâ)5: Will there be a strong wind ____ the north ______ the Huanghe River ?A:  to... ofB: to... offC: at... ofD: on… offÕýÈ·´ð°¸:(µ¥Ñ¡Ìâ)6: Scientific discoveries are often applied_____ industrial production methods.A: for B: with C: to D: onÕýÈ·´ð°¸:(µ¥Ñ¡Ìâ)7: I asked the bank for a _____.A: loafB: loadC: loanD: loamÕýÈ·´ð°¸:(µ¥Ñ¡Ìâ)8: The teacher required that all the assignments _____finished before this weekend.A: would beB: wereC: beD: are toÕýÈ·´ð°¸:(µ¥Ñ¡Ìâ)9:Everyone except Tom and John ______  there when the meeting began.A: isB: wasC: areD: wereÕýÈ·´ð°¸:(µ¥Ñ¡Ìâ)10: A good habit can make our mental health in      with physical health.A: concernB: connectionC: compareD: tuneÕýÈ·´ð°¸:(µ¥Ñ¡Ìâ)11:  May she _______ with you?A: comeB: comesC: comingD: cameÕýÈ·´ð°¸:(µ¥Ñ¡Ìâ)12: Which is the best approach _____ the tunnel?A: toB: withC: besidesD: towardsÕýÈ·´ð°¸:(µ¥Ñ¡Ìâ)13:He could_____ neither French or German,&n bsp;so I____ with him in English.A: speak, talkedB: talk, toldC: say, spokeD: tell, talkedÕýÈ·´ð°¸:(µ¥Ñ¡Ìâ)14:Don’t spend _______ time on compute r games.A: too muchB: much tooC: too manyD: many tooÕýÈ·´ð°¸:(µ¥Ñ¡Ìâ)15: Many girls like __________ skirts in summer.A: wearingB: dressingC: inD: putting onÕýÈ·´ð°¸:(µ¥Ñ¡Ìâ)16:Look! Lily with her sister _________&nbsp ;a kite on the playground.A: is flyingB: are flyingC: flyingD: flyÕýÈ·´ð°¸:(µ¥Ñ¡Ìâ)17: My home is about ________ from my school.A: 15 minutesB: minute's rideC: 20 minutes by bikeD: 15- minute's on foot.ÕýÈ·´ð°¸:(µ¥Ñ¡Ìâ)18:The policeman stopped ________, but he&nb sp;_______ no sound.A: hearing,heardB: listening,listenedC: to listen,heardD: listening to,listened toÕýÈ·´ð°¸:(µ¥Ñ¡Ìâ)19:  He walked ________ fast for us ________catch up with. A: so, thatB: such, thatC: enough, toD: too,toÕýÈ·´ð°¸:(µ¥Ñ¡Ìâ)20:  He failed the exam because he didn’t have      time(×ã¹»µÄÊ±¼ä) to prepare.A: rightB: spareC: adequateD: ownÕýÈ·´ð°¸:(µ¥Ñ¡Ìâ)21: The evidence found in this search is always incomplete and _____, it is also frequently partial.A: scatter  B: scattered C: scattering D:  scattered toÕýÈ·´ð°¸:(µ¥Ñ¡Ìâ)22: The museum has some new _____from India.A: exhibit B: exhibition C: exhibits D: exhibitionsÕýÈ·´ð°¸:(µ¥Ñ¡Ìâ)23: The organization performed an important _____ in protecting the rights of children.A: functionB: fictionC: fractionD: frictionÕýÈ·´ð°¸:(µ¥Ñ¡Ìâ)24: ---He can swim. ---_______ .A: So I canB: So can IC: I so canD: Can I soÕýÈ·´ð°¸:(µ¥Ñ¡Ìâ)25:  He ________ living in the country to the city. A: likesB: prefersC: enjoysD: lovesÕýÈ·´ð°¸:(µ¥Ñ¡Ìâ)26: What kind of music is your_____?A: favorableB: favoriteC: favorD: fateÕýÈ·´ð°¸:(µ¥Ñ¡Ìâ)27: --Must we finish our homework now?--No, you ______. You _______ finish it after school.A: needn't , mayB: mustn't , mayC: can't , canD:  needn't , mustÕýÈ·´ð°¸:(µ¥Ñ¡Ìâ)28: -- You seem to like sweets. --________ . I buy sweets every week.¡¡¡¡ A: So do IB: So I doC: So am ID: So I amÕýÈ·´ð°¸:(µ¥Ñ¡Ìâ)29: It is not _____to quarrel with your boss.A: worthyB: worthC: valueD: valuableÕýÈ·´ð°¸:(µ¥Ñ¡Ìâ)30: --Would you give me some water?  --____________.A: Yes, I wouldB: CertainlyC: No, thanksD: Yes,pleaseÕýÈ·´ð°¸:(ÔÄ¶ÁÀí½â)31:     He was struggling to tie his shoes.I was struggling with whether I should help him.    I did, and he was grateful.“Thank you,” he said.“I’m glad I could help. I just thought it would be easier for me to reach,” I said.    He was a disabled man, and forced to look down most of the time. His arms and legs were twisted terribly, and he couldn’t do what the rest of us would consider easy tasks. He always managed to look up to see how you reacted to his words, however. He had a big smile, making me feel comfortable.     I was still on my knees by his wheelchair.“ Nice shoes,” he said.“Thanks. No one ever complimented me on them before,” I said.“No one has the same view of the world as I do,” he replied.“Tell me about the world as you see it,” I said smiling.“Most people can see if someone is comfortable with them or not in their eyes. I see it in their feet.” he said. “If people keep moving their feet, I just let them go, because I know they’re impatient with me. I don’t want to make people uncomfortable.“What about me? I asked.“I could see your compassion. And then you came down to my level. I was the one who was nervous.” he said. “I don’t normally have someone look me in the eye.”“They don’t know what they’re missing,” I told him.“My old face is nothing to brag about.” he said.“But that smile is so big.”    Yes, and it’s not only a big smile but an attitude.ÕýÈ·´ð°¸:(ÔÄ¶ÁÀí½â)32:     My summer hols wr CWOT. B4. we usd 2 go 2 NY 2C my bro, his GF £¦ thr 3 : -@ kids FTF. ILNY, its gr8.    Can you understand this sentence? If you can’t, don't feel too bad: neither could the middle school teacher in England who received this as homework. This is Netspeak: the language of computerized communication found on Internet or cellphones. To newcomers, it ran like a completely foreign language. So, what is the "translation" of the sentence above? My summer holidays were a complete waste of time. Before, we used to go to New York to see my brother, his girlfriend, and their three screaming kids face to face.I love New York; it’s great.    Schoolteachers and parents say this new form of writing is harming the English language. Increasing spelling and grammatical mistakes can be seen in students' writing. They fear the language could become corrupted (ÃæÄ¿È«·ÇµÄ).    Everyone should just relax, say linguists (ÓïÑÔÑ§¼Ò). They believe Netspeak is in fact more of a good thing. David Crystal, from the University of Wales, argues that Netspeak and Internet create a new language use and the almost lost art of diary writing has been picked up again. Geoffrey Nunberg, from Stanford University, agrees. "People get better at writing by writing," he says, “Kids who are now doing text messaging, e-mail, and instant messages will write at least as well as, and possibly better than their parents."    Linguist James Milroy says, for centuries, it is believed without exception that young people are harming the language. And you can bet your bottom dollar that when today's teenagers become tomorrow's parents, they too will think this way, Milroy argues that languages do not and cannot become "corrupted"; they simply change to meet the new needs.    However, Netspeakers do agree that it is important to teach young people how to speak and write Standard English. Cynthia McVey says, "I can understand Netspeak worries teachers and it's important that they get across to their pupils that text messaging is for fun, but that learning to write proper English is a must for their future.”    Perhaps we should give teenagers a little more trust anyway. Erin, age 12, says, "I wouldn't use text language in my homework. Texting is just for fun."ÕýÈ·´ð°¸:(ÔÄ¶ÁÀí½â)33:     What might the future be like? Here are some predictions: things to come, things to go.    。

东大20秋学期《计算机辅助设计》在线平时作业1参考答案

20秋学期《计算机辅助设计》在线平时作业1
试卷总分:100得分:100
一、单选题(共10道试题,共50分)
1.阵列时，当行偏移为正值时，往( )偏移
A.上
B.下
C.左
D.右
答案:A
2.在CAD中执行“附着外部参照”命令的快捷键是( )
A.at
B.ax
C.x
D.xa
答案:D
3.在CAD中快捷键xl是( )
14.基线标注命令必须在执行了线性标注、对齐标注、角度标注或坐标标注之后才能使用。
答案:正确
15.单比例布图可以直接在模型空间出图打印。
答案:正确
16.填充图案选项板中，ANSI是国际标准化组织建议使用的填充图案。
答案:错误
17.单行文字的每一行是一个单独的整体，不可分解。
答案:正确
18.“主单位”选项卡只可以用来设置标注的主单位的格式和精度。
A.样条曲线
ห้องสมุดไป่ตู้B.直线
C.射线
D.构造线
答案:D
4.在CAD中修剪命令的的快捷键是( )
A.r
B.tr
C.tc
D.ts
答案:B
5.在“选择对象”的提示下，输入( )可以切换到“删除”模式
A.a
B.s
C.r
D.f
答案:C
6.在CAD中圆角命令的的快捷键是( )
A.r
B.a
C.s
D.f
答案:D
7.在CAD中如果执行了缩放命令的“全部”选项后，图形在屏幕上变成很小的一个部分，则可能出现的问题是( )
A.溢出计算机内存
B.将图形对象放置在错误的位置上
C.栅格和捕捉设置错误
D.图形界限比当前图形对象范围大

东大18春学期《计算机基础》在线作业123满分答案

东大18春学期《计算机基础》在线作业123满分答案【XXX】[XXX]18春学期《计算机基础》在线作业1试卷总分:100得分:100C、在打印机上打印该文档正确答案:B第2题,Internet Explorer浏览器本质上是一个____。

A、连入Internet的TCP/IP程序B、连入Internet的SNMP程序C、浏览Internet上Web页面的服务器程序D、浏览Internet上Web页面的客户端程序正确答案:D第3题,人们常说386微机、486微机，其中的数字指的是()。

A、硬盘的型号B、软盘的型号C、表现器的型号D、CPU的型号正确答案:D第4题,目前大多数计算机，就其工作原理而言，基本上采用的是科学家()提出的存储程序控制原理。

A、XXXB、XXXC、XXXD、XXX.XXX精确答案:B第5题,现在多媒体计算机中对动态图象数据压缩常采用____。

A、JPEGB、GIFC、MPEGD、BMP精确答案:C第6题,发送电子邮件采用的传输协议是____。

A、SMTPB、XXXC、HTTPD、FTP精确答案:A第7题,计算机网络按照联网的计算机所处位置的远近不同可分为()两大类。

A、城域网络和远程网络B、局域网络和广域网络C、远程网络和广域网络D、局域网络和以太网络精确答案:B第8题,使用InternetExplorer浏览时，按住()键的同时并点击链接可以新打开一个所点击链接的窗口。

A、ShiftB、CtrlC、AltD、Shift+Ctrl正确答案:A第9题,Internet起源于()。

A、美国B、英国C、德国D、澳大利亚精确答案:A第10题,下列四条叙述中，正确的一条是()。

A、操作系统是一种重要的应用软件B、外存中的信息可直接被CPU处理C、用机器语言编写的程序可以由计算机直接处理D、电源关闭后，ROM中的信息立即丢失正确答案:C第11题,Windows中的“剪贴板”是()。

A、硬盘中的一块区域B、软盘中的一块区域C、高速缓存中的一块区域D、内存中的一块区域正确答案:D第12题,Excel是一个电子表格软件，其主要作用是_____。

东大19春学期《结构抗震设计》在线作业3(100分)

19春学期《结构抗震设计》在线作业3在确定地震影响系数时，所考虑的因素包括Ⅰ、结构自振周期Ⅱ、设防烈度Ⅲ、近震还是远震Ⅳ、场地类别Ⅴ、特征周期Ⅵ、用于第一还是第二阶段设计Ⅶ、该系数的下限值A.Ⅰ、Ⅱ、Ⅲ、Ⅴ、ⅦB.Ⅰ、Ⅱ、Ⅲ、Ⅳ、ⅤC.Ⅲ、Ⅳ、Ⅴ、Ⅵ、ⅦD.Ⅰ、Ⅱ、Ⅴ、Ⅵ、Ⅶ正确答案:D多层内框架砖房的纵向窗间墙最小宽度A.7度为1.0mB.8度为1.2mC.不考虑设防烈度，均为1.2mD.不考虑设防烈度，均为1.5m正确答案:D里氏震级和地面振幅的关系是，震级相差一级，地面振幅相差A.10倍B.15倍C.25倍D.32倍正确答案:A地震震级与地震释放能量的关系是，震级增加一级时，能量约增加A.10倍B.15倍C.25倍D.32倍正确答案:D对于普通砖砌体承重的房屋，当设防类度为7度时，房屋总高度的限值为A.24mB.21mC.18mD.12m正确答案:B按照抗震设防烈度类别的划分，一般建筑属于A.甲类建筑B.乙类建筑C.丙类建筑D.丁类建筑正确答案:C当设防烈度为8度时采用现浇楼、屋盖的多高层钢筋混凝土房屋（无框支层）抗震墙之间楼、屋盖的长宽比一般不宜超过A.1.5B.2.0C.2.5D.3.0正确答案:D某18层普通高层住宅需进行抗震设防，其抗震设防类别应为A.甲类建筑B.乙类建筑C.丙类建筑D.丁类建筑正确答案:C构造柱、芯柱应先砌墙后浇注砼柱。

A.错误B.正确正确答案:B底框砖房底层的钢筋混凝土抗震墙的抗震等级可按二级采用。

A.错误B.正确正确答案:A强剪弱弯是指防止构件在弯曲屈服前出现脆性剪切破坏。

A.错误B.正确正确答案:B除强度与刚度要求外，在地震区结构要有良好的抵抗塑性变形的能力，即延性要求。

A.错误B.正确正确答案:B横墙较少的多层砌体房屋是指同一楼层内开间大于4.2m的房间占该层总面积40%以上的情况。

A.错误B.正确正确答案:B多层内框架砖房的纵向窗间墙宽度不应小于1m。

A.错误B.正确正确答案:A当建筑场地为Ⅰ类场地时，建筑可按原设防烈度降低一度采取抗震构造措施，地震作用仍按设防烈度计算，但6度时构造措施不应降低。

东大14秋学期《计算机硬件技术基础》在线作业3答案

14秋学期《计算机硬件技术基础》在线作业3单选题判断题一、单选题（共15 道试题，共75 分。

）1. 2.下列语句中能与“DAl DB 32H，34H”语句等效的是__。

A. MOV DA1，32H MOV DAI ＋l，34H"B. "MOV DA1，32 MOV DAI＋1，34"C. MOV WORD PTR DA1，3234 HD. MOV WORD PTR DAI，‘24’-----------------选择：A2. 2.DRAM是一种__。

A. 动态RAMB. 静态RAMC. 动态ROMD. 静态ROM-----------------选择：A3. 1.AX，BX中都是无符号数，如果AX>BX,转至NEXT处。

在CMPAX，BX指令后应选用的指令是__。

A. JNBE NEXTB. "JNLE NEXTC. "D. JBE NEXTE. JLE NEXT-----------------选择：A4. 1.运算器的核心部件是__.A. 数据寄存器B. 数据总线C. 累加器D. 算术逻辑单元-----------------选择：D5. 1.存储器的性能指标主要有速度、__和价格，三者之间通常是相互制约、相互矛盾的。

A. 性能B. 字长C. 存取方式D. 容量-----------------选择：D6. 3.在程序运行过程中，确定下一条指令的物理地址的计算表达式是__。

A. CS*16+IPB. DS*16+DIC. SS*16+DID. ES*16+SI。

东大19春学期《中国法制史》在线作业3

------------------------------------------------------------------------------------------------------------------------------ (单选题)1: 凌迟刑作为法定刑广泛使用始于( )。

A: 唐B: 宋C: 明D: 清正确答案:(单选题)2: 关于西周法制的表述,下列哪一选项是正确的?( )A: 周初统治者为修补以往神权政治学说的缺陷，提出了“德主刑辅，明德慎罚”的政治法律主张B: 《后汉书·陈宠传》称西周时期的礼刑关系为“礼之所去，刑之所取，失礼则入刑，相为表里”C: 西周的借贷契约称为“书约”，法律规定重要的借贷行为都须订立书面契约D: 西周时期在宗法制度下已形成子女平均继承制正确答案:(单选题)3: 刑法中的“折杖法”规定最早出现在( )。

A: 唐朝B: 宋朝C: 元朝D: 明朝正确答案:(单选题)4: 唐代的法律形式主要是( )。

A: 礼、刑、誓、诰B: 律、令、科、比C: 律、令、格、式D: 律、例、会典、章程正确答案:(单选题)5: 唐律规定,在斗杀过程中,错杀旁人的行为为( )。

A: 斗杀B: 戏杀C: 误杀D: 过失杀正确答案:(单选题)6: 中国历史上最后一部封建性质的成文法典是( )。

A: 《大清律例》B: 《大清律集解》C: 《大清律集解附例》D: 《大清现行刑律》正确答案:(单选题)7: 西周商品经济发展促进了民事契约关系的发展。

《周礼》载:“听买卖以质剂”。

汉代学者郑玄解读西周买卖契约形式:“大市谓人民、牛马之属,用长券;小市为兵器、珍异之物,用短券。

”对此,下列哪一说法是正确的?( )A: 长券为“质”，短券为“剂”B: “质”由买卖双方自制，“剂”由官府制作------------------------------------------------------------------------------------------------------------------------------ C: 契约达成后，交“质人”专门管理D: 买卖契约也可采用“傅别”形式正确答案:(单选题)8: 我国第一次公布成文法的人是春秋时郑国的( )。

东大19春学期《机械设计基础》在线作业3【标准答案】

(单选题)1: 一曲柄摇杆机构，若改为以曲柄为机架，则将演化为（    ）。

A: 曲柄摇杆机构B:  双曲柄机构C: 双摇杆机构D: 导杆机构正确答案:(单选题)2: 与齿轮传动相比，（    ）不能作为蜗杆传动的优点。

A: 传动平稳，噪声小B: 传动比可以较大C: 可产生自锁D: 传动效率高正确答案:(单选题)3: 凸轮机构的从动件选用等加速等减速运动规律时，其从动件的运动（    ）。

A: 将产生刚性冲击B: 将产生柔性冲击C: 没有冲击D: 既有刚性冲击又有柔性冲击正确答案:(单选题)4: 普通V带传动是依靠（    ）来传递运动和动力的。

A: 带与带轮接触面之间的正压力B: 带与带轮接触面之间的摩擦力C: 带的紧边拉力 D: 带的松边拉力正确答案:(单选题)5: （    ）轮系不能用转化轮系传动比公式求解。

A: 定轴B: 混合C: 行星D: 差动正确答案:(单选题)6: 角接触球轴承承受轴向载荷的能力随着接触角的增大而（    ）。

A: 增大B: 减少C: 不变D: 增大或减少随轴承型号而定正确答案:(单选题)7: 一减速齿轮传动，小齿轮1选用45号钢调质；大齿轮选用45号钢正火，它们的齿面接触应力（    ）。

A: 小齿轮大于大齿轮B: 小齿轮小于大齿轮C: 小齿轮等于大齿轮D: 小齿轮小于等于大齿轮正确答案:(单选题)8: 一对标准直齿圆柱齿轮，若 Z1=18，Z2=72，则这对齿轮的弯曲应力（    ）。

东大19春学期《计算机辅助设计》在线作业3【标准答案】

(单选题)1: 在CAD中定义块的属性的快捷键是( )A: atB: attC: adD: add正确答案:(单选题)2: 在CAD中倒角命令的的快捷键是( )A: cuB: cdC: chD: cha正确答案:(单选题)3: AutoCAD2008 提供了( )种绘制圆的方法A: 2B: 4C: 6D: 8正确答案:(单选题)4: 1500mm的窗宽，如果画成10个绘图单位，所采用的比例为( )A: 1:50B: 0.111111111C: 0.145833333D: 0.180555556正确答案:(单选题)5: 在CAD中定数等分的快捷键是( )A: MIB: LENC: F11D: DIV正确答案:(单选题)6: 绘制样条曲线时，至少需要输入( )个点A: 2B: 3C: 4D: 5正确答案:(单选题)7: 复制缩放是在命令提示行中输入( )，然后再输入比例因子或参照缩放，就会在原有对象仍然存在的情况下，再产生一个新的缩放后的对象。

A: CB: DC: FD: S正确答案:(单选题)8: 在CAD中快捷键xl是( )A: 样条曲线B: 直线C: 射线D: 构造线正确答案:(单选题)9: 在CAD中绘制正多边形的快捷键为( )A: aB: lC: plD: rec正确答案:(单选题)10: 在CAD中绘制圆弧快捷键是( )A: trB: aC: recD: pl正确答案:(判断题)11: 绘制样条曲线确定起点和终点的切线方向时，切线方向不同不会改变样条曲线的形状。

A: 错误B: 正确正确答案:(判断题)12: 已冻结的图层可以置为当前层。

A: 错误B: 正确正确答案:(判断题)13: 缩放命令和平移命令都是透明命令。

A: 错误B: 正确正确答案:(判断题)14: 块参照的x、y方向始终与块创建前的方向一致。

B: 正确正确答案:(判断题)15: 在AutoCAD中，可以将某些对象围成的封闭区域转化为面域。

东大20春学期《计算机辅助设计》在线平时作业3答卷

20春学期《计算机辅助设计》在线平时作业3
试卷总分:100 得分:100
一、单选题 (共 10 道试题,共 50 分)
1.在执行“延伸”命令的过程中，需要用户选择( )种对象
A.4
B.3
C.2
D.1
答案:C
2.在CAD中要始终保持物体的颜色与图层的颜色一致，物体的颜色应设置为( )
A.按颜色
B.按红色
C.按图层
D.图层锁定
答案:C
3.在CAD中定义块的属性的快捷键是( )
A.att
B.at
C.add
D.ad
答案:A
4.在CAD中用POLYGON命令画成的一个正六边形，它包含( )个图元
A.不确定
B.6个
C.2个
D.1个
答案:D
5.执行圆角命令时，可以输入( )来连续进行多次圆角处理
A.T
B.R
C.P
D.M
答案:D
6.AutoCAD2008 提供了( )种绘制圆的方法
A.8
B.6
C.4
D.2
答案:B。

东大22春《计算机应用基础》在线平时作业1【参考答案】

《计算机应用基础》在线平时作业1【参考答案】
试卷总分:100 得分:100
一、单选题 (共 25 道试题,共 100 分)
1.计算机系统的输入输出接口是____之间的交接界面。

A.CPU与存储器
B.主机与外围设备
C.存储器与外围设备
D.CPU与系统总线
标准答案:B
2.以下()文件类型属于视频文件格式且被PowerPoint所支持。

A.avi
B.wpg
C.jpg
D.winf
标准答案:A
3.在Excel中，如果在工作表中某个位置插入了一个单元格，则____。

A.原有单元格必定右移
B.原有单元格必定下移
C.原有单元格被删除
D.原有单元格根据选择或者右移、或者下移
标准答案:D
4.如果电子邮件到达时，你的电脑没有开机，那么电子邮件将____。

A.退回给发件人
B.保存在服务商的主机上
C.过一会儿对方重新发送
D.永远不再发送
标准答案:B
5.一个汉字和一个英文字符在微型机中存储时所占字节数的比值为____。

A.4:1
B.2:1
C.1:1
D.10:1
标准答案:B
6.合法的IP地址是____。

A.202:196:112:50
B.202、196、112、50
C.202,196,112,50
D.202.196.112.50
标准答案:D。

东大19春学期《计算机辅助设计基础》在线作业3【标准答案】

(单选题)1: 下面哪个坐标系是一个符合左手定则的直角坐标系？A: 世界坐标系B: 观察坐标系C: 规格化设备坐标系D: 设备坐标系正确答案:(单选题)2: 下列关于当前3C系统内部集成描述正确的是：A: 形成了统一的产品模型B: 系统的异构性C: 现有商用CAD/CAM系统中缺乏CAMD: 以上都不对正确答案:(单选题)3: OpenGL属于CAD支撑软件的哪一类？A: 基本图形资源软件B: 二、三维绘图软件C: 几何造型软件D: 工程分析及计算软件正确答案:(单选题)4: 下面哪种模型的棱线是有向的？A: 线框模型B: 表面模型C: 曲面造型D: 实体造型正确答案:(单选题)5: 下面哪一种不是常见的数控编程的自动编程方式？A: 采用数控编程语言的自动编程B: 从CAD获取信息的自动编程C: 从CAPP获取信息的自动编程D: 计算机辅助图形设计的自动编程正确答案:(判断题)6: 线性表的链式存储结构中的存储单元一定是不连续的。

A: 错误B: 正确正确答案:(判断题)7: 在AutoCAD系统中，MIRROR命令可以绘出对称的图形，但原图不再保留。

A: 错误B: 正确正确答案:(判断题)8: 参数化设计是一种设计方法，采用尺寸驱动的方式改变由几何约束构成的几何模型。

A: 错误B: 正确正确答案:(判断题)9: 线性表中的数据元素可以是一个数、一个符号，也可以是一个线性表。

A: 错误B: 正确正确答案:(判断题)10: PDM是PLM的基础，PLM 是PDM功能的延伸。

A: 错误B: 正确正确答案:(判断题)11: 20世纪50年代末，开始用线框和多边形构造三维形体，这样的模型被称为线框模型。

A: 错误B: 正确正确答案:(判断题)12: 3C系统的内部集成主要是指三类软件的集成，即CAD、CAE和CAM，写成CAD/ CAE/CAM。

A: 错误B: 正确正确答案:(判断题)13: 遍历二叉树是指按照一定的规律走遍二叉树的每个结点，每个结点可能被访问多次。

东大19秋学期《计算机辅助设计》在线平时作业1参考答案

19秋学期《计算机辅助设计》在线平时作业1
试卷总分:100 得分:100
一、单选题 (共 10 道试题,共 50 分)
1.在CAD中为了保证整个图形边界在屏幕上可见，应使用哪一个缩放选项( )
A.范围
B.图形界限
C.全部
D.上一个
答案:C
2.在夹点镜像时，按住( )键，可以在镜像后保留源对象
A.Shift
B.F11
C.F1
D.Ctrl
答案:D
3.在CAD中使用POLYGON命令绘制正多边形，边数最大值是( )
A.50
B.300
C.1024
D.100
答案:C
4.在CAD中打开“栅格”命令的快捷键是( )
A.F7
B.F6
C.F3
D.F1
答案:A
5.在CAD中绘制正多边形的快捷键为( )
A.a
B.l
C.pl
D.rec
答案:C
6.在CAD中绘制椭圆时，确定椭圆的参数不包括下列哪项( )
A.长轴
B.短轴
C.椭圆上的点
D.椭圆中心
答案:C
7.在CAD中绘制多线的快捷键是( )
A.pl。

东大14秋学期《计算机辅助设计基础》在线作业1答案

14秋学期《计算机辅助设计基础》在线作业1
一,单选题
1. Cohen-Sutherland算法称为？
A. 编码裁剪算法
B. 矢量裁剪算法
C. 中点分割裁剪算法
D. 以上都不是
?
正确答案：A
2. 在C/S的哪一种分布模式中，客户信息被多个服务器接受，但不要求返回响应？
A. 任务承包模式
B. 单客户－多服务器模式
C. 广播模式
D. 链式服务器模式
?
正确答案：C
3. 机械设计过程一般经历三个阶段，下面哪一个不属于？
A. 概念设计
B. 完善设计
C. 初步设计
D. 详细设计
?
正确答案：B
4. 下面哪个坐标系采用无量纲的单位？
A. 世界坐标系
B. 观察坐标系
C. 规格化设备坐标系
D. 设备坐标系
?
正确答案：C
5. AutoCAD中，用编辑命令一次可去掉多条长出某直线的线条。

A. ERASE
B. TRIM
C. BREAK
D. UNDO
?
正确答案：B。