连接 练习题

宾语从句专项练习一、将下面的句子连接成为含有宾语从句的复合句。

1.These flowers are from Guangdong. He said.He said these flowers from Guangdong.2.Light travels faster than sound. My teacher told me.My teacher told me light faster than sound.3 ・ There will be a meeting in five days. Jack didn't know.Jack didn't know there a meeting in five days.4. Can they speak French? I want to know.I want to know French.5 ・ Are the children playing games? Tell me.Tell me the children games.6.Have you finished your homework yet? Mr. Zhao asked Ma Gang.Mr. Zhao asked Ma Gang homework yet.7.How many people can you see in the picture? Who knows?Who knows in the picture?8.Where did she park her car? Do you know?Do you know her car?9.What does he often talk about? The girl wondered.The girl wondered often about.10.Who knocked at the door so loudly? I don't know.I don91 know at the door so loudly.11.Does he still live in that street? I don't know.I don't know he still in that street.12.What's his name? I asked him.I asked him what.13.When does the train arrive? Please tell me.Please tell me.14.Do they want fried chicken? He asked the boys.He asked the boys they fried chicken.15.Was the watch made in Shanghai? I don't know.I don't know the watch made in Shanghai.二、选择填空。

金属材料焊接练习题库及答案一、判断题（共100题，每题1分，共100分）1、焊接是通过加热或加压 ,或两者并用,并且用或不用填充材料 ,使焊件达到原子结合的一种加工方法。

（）A、正确B、错误正确答案：A2、起重机械是指用于垂直升降或者垂直升降并水平移动重物的机电设备。

（）A、正确B、错误正确答案：A3、熔化极氩弧焊的供气系统和钨极氩弧焊不同。

（）A、正确B、错误正确答案：B4、螺柱焊焊接时,应保持焊枪与工件表面垂直。

( )A、正确B、错误正确答案：A5、低合金高强钢焊接时,适当提高预热温度和增加焊接线能量可以防止产生冷裂纹。

A、正确B、错误正确答案：A6、镍和铜可以无限互溶,所以镍铜合金不存在晶间腐蚀问题。

( )A、正确B、错误正确答案：A7、射线照相底片上的白色宽带表示焊缝,白色宽带中的黑色斑点或条纹就表示焊接缺陷。

（）A、正确B、错误正确答案：A8、等离子弧是压缩电弧。

( )A、正确B、错误正确答案：A9、采用接触引弧法是手工钨极氩弧焊最好的引弧方法。

( )A、正确B、错误正确答案：B10、电渣焊时熔化金属表面覆盖一层熔渣,因此氧化现象不严重。

( )A、正确B、错误正确答案：B11、工业纯钛可采用焊条电弧焊方法进焊接。

( )A、正确B、错误正确答案：B12、焊缝金属的力学性能和焊接热输入量无关。

（）A、正确B、错误正确答案：B13、“J422”是结构钢焊条牌号完整的表示方法,其中“42”表示焊缝金属的主要化学成分等级。

（）A、正确B、错误正确答案：B14、钨极氩弧焊接头起弧时, 应注意形成熔池后, 再填加焊丝。

( )A、正确B、错误正确答案：A15、奥氏体不锈钢主要的腐蚀形式是晶间腐蚀。

（）A、正确B、错误正确答案：A16、焊接时,焊接电流越大,越有利于熔渣的悬浮和分离,越不易产生夹渣,因此,焊接电流越大越好。

( )A、正确B、错误正确答案：B17、严禁在尚有压力的容器或管道上进行焊接。

2021年低压电工练习题和答案（Part10）共2种题型，共60题一、单选题(共30题)1.一台380伏7.5千瓦的电动机，装设过载和断相保护，应选()。

A：J6-20/3B：J6-60/3DC：J6-20/3D【答案】：C【解析】：查电机额定电流或计算额定电流Ie=7.5KW/（√3x280Vx0.8）=14.2A 选项中有两个符合，接下来判断哪个型号的热继电器带缺相保护功能即可。

一般标注“3D”为三相保护。

应选三相20A的过载和断相保护（JR16-20/3D），JR16-60/3D的额定电流太大。

2.下列灯具中功率因数最高的是()。

A：白炽灯B：节能灯C：日光灯【答案】：A【解析】：功率因数，是衡量用电设备对于电源的能量的利用效率的数据。

白炽灯是纯电阻性的，它在工作中，不会对交流电产生电流移相，电压和电流始终保守同相，其功率因数=1，最大值。

而日光灯，早期的是使用电感镇流器，电感会导致电流相位滞后，从而导致日光灯功率因数降低，通常是0.85左右。

现在的日光灯，一般采用电子镇流器，功率因数虽然提高很多，但是始终小于1，通常是0.95～0.98左右。

如果是黑心企业生产的，他们会在线路上节省很多该用不用的元件，会导致功率因数更低，通常只有0.92左右。

节能灯，实际上是采用电子镇流器的小型化的日光灯。

所以参照前面的即可。

注意：功率因数，不同于电灯的发光效率。

发光效率，是同样的电能灯泡可以发出的光的强度。

因为日光灯、节能灯的发光效率远远高于白炽灯，也就是说，同样的光亮，日光灯节能灯的耗电要小很多，所以，我们提倡少用白炽灯。

3.引起电光性眼炎的主要原因是()。

A：红外线B：可见光C：紫外线【答案】：C【解析】：电光性眼炎多在电焊或气焊时，由电弧与溶化金属产生的紫外线照射后引起；也可由紫外线消毒、太阳灯照射等所致；亦有在冰川、高原、雪地、海面、沙漠等地工作，因受阳光照射后反射之紫外线所伤者，故又名雪盲。

致伤的紫外线波长范围在320~350nm之间。

单元2 钢结构的连接复习思考题2-1钢结构的连接方式有几种？各有何特点？目前常用哪些方法？答：钢结构的连接方法有焊缝连接、铆钉连接和螺栓连接三种。

焊缝连接：1）优点：构造简单，任何形式的构件都可直接相连；用料经济、不削弱截面；制作加工方便，可实现自动化操作；连接的密闭性好，结构刚度大。

2）缺点：在焊缝附近的热影响区内，钢材的金相组织发生改变，导致局部材质变脆；焊接残余应力和残余变形使受压构件承载力降低；焊接结构对裂纹很敏感，局部裂纹一旦发生，就容易扩展到整体，低温冷脆现象较为突出。

螺栓连接：1）优点：施工工艺简单、安装方便，特别适用于工地安装连接，工地进度和质量易得到保证；且由于装拆方便，适用于需装拆结构的连接和临时性连接。

2）缺点：螺栓连接需制孔，拼装和安装需对孔，增加了工作量，且对制造的精度要求较高；此外，螺栓连接因开孔对截面有一定的削弱，有时在构造上还须增设辅助连接件，故用料增加，构造较繁。

在钢结构工程中，焊缝连接、螺栓连接是最常用的连接方法。

铆钉连接：1）优点：铆钉连接的塑性和韧性较好，传力可靠，质量易于检查。

2）缺点：构造复杂，费钢费工。

2-2对接焊缝的坡口形式主要由什么条件决定？通常用的坡口形式有哪几种？并绘图示意。

答：对接焊缝的坡口形式取决于焊件厚度t 。

常用对接焊缝的坡口形式有以下6种：（a）直边缝（b）单边V形坡口（c）V形坡口（d）U形坡口（e）K形坡口（f）X形坡口2-3对接焊缝在哪种情况下才需要进行抗拉强度计算？答：由于一、二级质量的焊缝与母材强度相等，故只有三级质量的焊缝才需进行抗拉强度验算。

2-4引弧板起什么作用？答：引弧板可消除焊缝的起灭弧处弧坑等缺陷，避免产生应力集中和裂纹。

2-5焊缝的起弧、落弧对焊缝有何影响？对接焊缝和角焊缝计算中如何考虑？ 答：焊缝的起弧、落弧易产生弧坑等缺陷，使焊缝的计算长度减小。

对接焊缝：若未加引弧板，则每条焊缝的引弧及灭弧端各减去t （t 为较薄焊件厚度）后作为焊缝的计算长度。

连词练习题(附答案)一、从属连词1．He was so busy. He cannot afford enough time with his son ________ he really wants to. A．as if B．even if C．in case D．before long2．I like the city, but I like the country better I have more friends there.A．in which B．for which C．in that D．at that3．You will never achieve success _______ you keep working hard.A．when B．if C．unless D．because4．He hasn’t got any hobbies—________ you call watching TV a hobby.A．if B．as long as C．unless D．although5．________ things had been tough at times when he was in school, he graduated from college with the highest honor.A．If B．While C．Because D．As6．We’ve been friends________we came to this school a year ago.A．when B．for C．before D．since7．--- Will you go to the history museum tomorrow?--- Sure I will, ________ it doesn’t rain heavily.A．in case B．as if C．as long as D．even if8．________ he is determined to do something, no one is able to persuade him to________. A．If; give away B．Although; give in C．As long as; give out D．Once; give up 9．The little girl won’t go to sleep at noon _______ her mother tells her a story.A．or B．but C．if D．unless 10．Don’t stop ________ you meet with a word you don’t understand.A．at that time B．each time C．sometimes D．before11．______ the man isn’t very rich, he gives a large amount of money to the students every year. A．Though B．Since C．Unless D．If12．______ you have set your mind on the goal, you must try your best to achieve it. A．Though B．Unless C．Once D．While13．She remembered it________ it were yesterday and knew it would haunt her forever.A．as though B．even though C．as soon as D．the moment 14．The writer always carries a notebook along with him, ________ he is seized by sudden inspiration.A．in case B．even though C．now that D．the moment 15．It’s mor e than half a century ________ my grandfather joined the Party and became a servant to the people.A．when B．that C．since D．as 16．Travelers will be unable to go to the city________ they have a booking in a restaurant or hotel.A．if B．because C．while D．unless17．_________ you try to do something beyond what you have already mastered, you will never grow.A．Once B．If C．Because D．Unless18．The two girls kept talking in the room ________ their mothers said goodbye to each other. A．when B．unless C．while D．until19．______ the fire broke out, all the students were sleeping soundly.A．Because B．In case C．When D．As long as 20．They were staring at me _______ I were some kind of an alien（外星人）.A．even if B．if only C．only if D．as if二、并列连词21．______, the students in Shiyan High School do about 3000 meters every day, ______ their parents may do far more than that.A．In theory; but B．On average; whileC．In particular; when D．In response; where22．- All the salt is sold out!- People are crazy! experts say there is no use eating salt to prevent radiation(辐射), some people still don’t believe it.A．Unless B．AlthoughC．As a result D．In order that23．It looked like rain. , it is clear this morning.A．While B．ButC．However D．So24．Be careful ______ you’ll make fewer mistakes.A．or B．asC．and D．but25．He missed the worst of the traffic this morning, ______ he set out before 6 o’clock. A．but B．soC．for D．or26．【2018·海淀二模】—Excuse me, sir. Can you spare me a dollar ________ I can buy this book?—Sure, no problem.A．for B．soC．but D．or27．I had just got up and was about to cook my breakfast______ the telephone rang loudly, but it hung up ______ I could answer it.A．while; when B．when; asC．as; after D．when; before28．I hope you don’t mind me asking, ________ where did you b uy those shoes?A．so B．and C．yet D．but29．The artist was born poor, poor he remained all his life.A．and B．or C．but D．so30．Give me your email address，____________ I’11 send you the form·A．or B．and C．but D．nor31．Tom is really good at science, his brother is a natural artist.A．while B．becauseC．for D．as32．There’s no way of knowing why one man makes an important discovery __________ another man, also intelligent, fails.A．while B．when C．where D．why33．—How does your mother like your presents f or Mother’s Day?—Well, this sweater that one is fit for her. They’re too big.A．both; and B．either; orC．neither; nor D．not only; but also34．—I hear Susan will go to Beijing by herself.—That’s true her father her mother will go with her.A．both, and B．either, or C．neither, nor35．I thought we’d be late for the concert, ______ we ended up getting there ahead of time. A．but B．or C．so D．for36．Notices in the waiting room requested that you can neither smoke ________ shout loudly. A．and B．or C．so D．nor37．Tom is a quiet student in class, _______________ he is quite active in outdoor activities. A．so B．and C．because D．but38．Which one of the following sentences is the compound sentence(并列句)?A．Playing football and dancing are his favourites.B．The good news is that this stormy period will not last.C．You feel ready to be more responsible and make decisions on your own.D．I don’t know what “home” is, but unhappiness and worries melt away once there. 39．Walk along this road for 100 meters ________ you’ll see the hospital.A．or B．otherwise C．and D．or else 40．Some people like dogs______ others like cats.A．while B．besidesC．and so D．when【参考答案】一、从属连词【解析】【详解】考查连词词义辨析。

《螺纹连接练习题》一、单选题(每题1分)1. 采用凸台或沉头座其目的为。

A 便于放置垫圈B 避免螺栓受弯曲力矩C 减少支承面的挤压应力D 增加支承面的挤压应力2. 联接螺纹要求自锁性好，传动螺纹要求。

A 平稳性B 效率高C 螺距大D 螺距小3. 连接用的螺纹，必须满足条件。

A 不自锁B 传力C 自锁D 传递扭矩4. 单线螺纹的螺距导程。

A 等于B 大于C 小于D 与导程无关5. 同一螺栓组的螺栓即使受力不同，一般应采用相同的材料和尺寸，其原因是。

A 便于装配B 为了外形美观C 使结合面受力均匀 D 减少摩损6. 用于联接的螺纹，其牙形为。

A 矩形B 三角形C 锯齿形D 梯形7. 螺纹的标准是以为准。

A 大径B 中径C 小径D 直径8. 螺纹的危险截面应在上。

A 大径B 小径C 中径D 直径9、在常用的螺旋传动中，传动效率最高的螺纹是__________。

A三角形螺纹B梯形螺纹C锯齿形螺纹D矩形螺纹10、在常用的螺纹联接中，自锁性能最好的螺纹是__________。

A三角形螺纹B梯形螺纹C锯齿形螺纹D矩形螺纹11、当两个被联接件不太厚时，宜采用__________。

A双头螺柱联接B螺栓联接C螺钉联接D紧定螺钉联接12、当两个被联接件之一太厚，不宜制成通孔，且需要经常拆装时，往往采用__________。

A螺栓联接B螺钉联接C双头螺柱联接D紧定螺钉联接13、当两个被联接件之一太厚，不宜制成通孔，且联接不需要经常拆装时，往往采用__________。

A螺栓联接B螺钉联接C双头螺柱联接D紧定螺钉联接14、普通螺纹的牙型角α为60o，当摩擦系数μ＝0.10时，则该螺纹副的当量摩擦系数μv＝__________。

A0.105 B 0.115 C 0.1115 D 0.10415、在拧紧螺栓联接时，控制拧紧力矩有很大方法，例如__________。

A增加拧紧力B增加扳手力臂C使用测力矩扳手或定力矩扳手16、螺纹联接防松的根本问题在于__________。

语言连贯练习题语言连贯是指通过恰当使用连接词、代词、过渡词等手段，使文章的句子和段落之间有机地衔接起来, 实现信息的连贯性和阅读的流畅性。

下面将给出一系列语言连贯练习题，帮助您更好地理解和掌握语言连贯的技巧。

练习题一：句子连接将下列句子连接成流畅的段落，并尝试使用连词或链接词进行衔接。

1.我经常去图书馆看书。

2.我喜欢阅读各种类型的图书。

3.图书馆的环境非常安静。

4.在图书馆里，读书的氛围非常浓厚。

练习题二：过渡词使用选择适当的过渡词填空，将下列句子连接起来。

1.我喜欢旅行。

2.旅行可以让我放松心情。

3.我还可以领略各地的风土人情。

4.另外，旅行也是一种学习和成长的机会。

练习题三：段落连接将下列独立的段落按照逻辑关系重新排列，使其更加连贯。

段落A：夏天的时候，我经常去游泳。

游泳可以锻炼身体，同时还可以消暑。

段落B：每天，我都会花一些时间学习，以提高自己的知识水平。

学习对我来说是一种乐趣和追求。

段落C：周末的时候，我喜欢和好朋友一起去看电影。

电影能够让我们放松心情，一同度过愉快的时光。

练习题四：代词使用使用恰当的代词填空，将下列句子连接起来。

1.玛丽是一个很友好的人。

2.我经常和玛丽一起参加社交活动。

3.她总是邀请我参加各种聚会。

4.我们彼此之间有很好的沟通。

练习题五：逻辑关系将下列句子按照逻辑关系进行排序，形成连贯的段落。

1.大学生需要学习专业知识，掌握实用技能。

2.同时，大学生也应该培养自己的综合素质。

3.这包括语言表达能力、团队合作能力以及创新思维等。

4.只有综合素质与专业知识相结合，才能更好地适应社会的发展。

练习题六：因果关系选择适当的连接词或短语，使下列句子在因果关系上连贯起来。

1.我每天早上都锻炼身体。

2.因为我想保持健康。

3.锻炼身体可以增强我的体质。

4.所以我每天都坚持锻炼。

以上是语言连贯练习题，希望对您的学习有所帮助。

通过不断练习和积累，您的语言连贯能力将会得到提升，使您的写作更加流畅和连贯。

链连接习题集1.键16×10×100 GB1096中参数16是（ A ）A、键宽B、键高C、键长D、键的工作长度2.b×h×L相同的三种普通平键，有效工作长度最大的是（ A ）A、圆头B、平头C、半圆头D、一样大3.轴上A型平键键槽的横截面尺寸取决于（B ）A、键的长度B、轴的长度C、轮毂的长度D、轴的直径4.普通平键连接不满足强度条件时，可采用双键，其合理的布置应使它们沿圆周相隔（ D ）A、90°B、135°C、150°D、180°5.在键长为L键宽为b的普通平键连接的强度校核中，A型平键的有效工作长度l（B ）A、l = LB、l = L – bC、l = 2bD、l = b/26.齿轮轮毂长度为30mm，安装齿轮的轴头部分A型普通平键键槽长度应加工为（ B ）A、16mmB、25mmC、32mmD、35mm7.尺寸b×h×L相同的普通平键中，受挤压面积最大的（ B ）A、A型B、B型C、C型D、A型或B型8.普通平键连接的两个键按180°布置，进行强度校核时，需按照几个键进行（ C ）A、1.2B、1.5C、1.5D、29.键的截面尺寸b×h，其选择的主要依据是（ B ）A、轮毂长度B、轴的直径C、传递扭矩的大小D、传递功率的大小10.键16×10×100 GB1096中参数100是（ A ）A、零件轮毂的宽度B、安装键部位的轴颈C、传递载荷大小D、有效工作尺寸11.变速箱中滑移齿轮轴向移动量不大时，应选用（ C ）A、普通平键B、半圆键C、导向平键D、楔键12.平键标记为：“键16×10×100 GB1096”中键的高度是（ C ）A、16mmB、100mmC、10mmD、无法确定13.平键标记为：“键16×10×100 GB1096”中键是（ A ）A、平头平键B、半圆键C、圆头平键D、半圆头平键14.对于平键的标准代号，说法正确的是（ B ）A、“键”可以省略B、“键”不可以省略C、B型键“B”可以省略D、“GB/T1096”可以省略15._________连接应用最广，适用于高精度，高速或承受变载、冲击的场合。

西门子PLC练习题库一、填空题（共29题）1.在PLC中当输出继电器Q线圈得电后，其对应地址的常闭触头（），常开触头（）。

[填空题]_________________________________(答案：断开；闭合)2. （）模块是可编程序控制器系统的运算控制核心。

[填空题]_________________________________(答案：CPU)3.按结构形式分类，PLC可分为（）式和（）式两种。

[填空题]_________________________________(答案：整体；模块)4.下载程序时，PLC的运行模式应处于（）时才能进行下载。

[填空题]_________________________________(答案：Stop)5.可编程序控制器系统也称之为“软接线”程序控制系统，由（）和（）两大部分组成。

[填空题]_________________________________(答案：硬件；软件)6. PLC的工作过程一般可分为三个主要阶段（）、程序执行阶段和（）。

[填空题]_________________________________(答案：输入采样阶段；输出刷新阶段)7.定时时间等于时基和定时值的（）。

[填空题]_________________________________(答案：乘积)8. PLC软件系统有（）和（）两大部分。

[填空题]_________________________________(答案：系统程序；用户程序)9.在S7-200系列的PLC中有三种计数器，分别是（）、减计数器和（）。

[填空题]_________________________________(答案：加计数器；加/减计数器)10.可编程序控制器是一种专为工业环境下应用而设计的计算机控制系统，通过（）、（）的输入和输出完成各种机械生产过程的控制。

[填空题]_________________________________(答案：开关量；模拟量)11.通电延时定时器（TON）的输入（IN）电路（）时开始定时，当前值大于等于设定值时，其定时器位变为1状态，其常开触点（），常闭触点（）。

二年级数字连线练习题
欢迎参加小学二年级数学练习！本次练习主题是数字连线。

请你根据下面的问题，将正确的数字与相应的图形线连接起来。

每个问题只有一个正确答案，请仔细阅读问题并选择正确的答案。

1. 请将数字和相应的图形线连接起来。

- 1与正方形相连
- 2与圆形相连
- 3与三角形相连
- 4与长方形相连
2. 请将数字和相应数量的图形线连接起来。

- 将3与三个圆形相连
- 将2与两个正方形相连
- 将5与五个长方形相连
- 将1与一个三角形相连
3. 请将数字和相应的数目线连接起来。

- 将2与两条线相连
- 将4与四条线相连
- 将6与六条线相连
- 将8与八条线相连
4. 请将数字和相应的图形数量连接起来。

- 将6与六个三角形相连
- 将3与三个长方形相连
- 将5与五个正方形相连
- 将2与两个圆形相连
5. 请将数字和相应的单词连接起来。

- 将1与one相连
- 将4与four相连
- 将3与three相连
- 将5与five相连
6. 请将数字和相应的图形名称连接起来。

- 将2与圆形相连
- 将3与三角形相连
- 将4与长方形相连
- 将1与正方形相连
完成以上练习后，你已经掌握了数字与图形之间的对应关系。

希望这次练习能帮助你更好地理解数字和图形的关系，并提高你的数学能力。

加油！。

连词练习题(及答案)经典一、从属连词1．Fortunately, someone called the fire department ________ the fire broke out.A．instantly B．the instantly C．instant D．an instant2．______ I saw my father ,I burst into tears.A．The instant B．both A and D C．At the instant D．Instantly3．you could imagine, if the first aid was given in time, the injured would be saved.A．When B．If C．Unless D．As4．Just accept the disabled for ________they are, and give them encouragement to live as rich and full a life ________you do.A．whom; so B．which; like C．who; as D．that; as 5．Chinese overseas students are encouraged to return, ________ they honestly fill out medical forms and strictly follow the quarantine（隔离期）rules.A．though B．as long as C．unless D．as if6．______ he met with the difficulty did he realize the importance of group work.A．Even though B．Only before C．Never until D．Ever since7．He was wondering in the street _________ he felt patted on the shoulder.A．as B．when C．while D．where8．________ focusing on what you lack, try noticing what you have. You may gradually feel better.A．More than B．Other than C．Rather than D．Less than9．__________ I like the color of that hat, I don’t like its shape.A．That B．While C．As D．So10．Please keep an eye on the stove ________ the milk boils.A．in memory of B．so that C．in case D．apart from 11．We packed all the books in the boxes________they wouldn't get damaged.A．as long as B．as if C．in case D．so that12．It’s not surprising ________ you won the medal, considering how much you paid for it. A．whether B．why C．because D．that13．I was really excited about the plane trip ______ I got on the plane and saw the narrow space between the seats.A．once B．where C．though D．until14．________ the learning is slow and painful, the result is wonderful.A．As B．Unless C．Even though D．Since15．We will visit the Olympic Village ________ it rains tomorrow.A．unless B．as soon as C．when D．since 16．Handwritten documents are more valuable to researchers, historians say, ________ their reliability can be confirmed.A．though B．so that C．while D．because17．The shepherd and his dog set out early in the morning ________they could drive the flock of sheep to the valley before the noon.A．because B．before C．so that D．while18．If the country is fully employed, its boom industries cannot grow ______ other industries shrink.A．if B．unless C．lest D．for19．The two girls kept talking in the room ________ their mothers said goodbye to each other. A．when B．unless C．while D．until20．Dr. Zhong advised the public not to go to the crowded places ________ they should be infected with Covid-19.A．even if B．in case C．as long as D．now that二、并列连词21．He always had his camera ready whenever he traveled, just he saw something that would make a good picture.A．in case B．so that C．for fear that D．as if22．Be carefu l ______ you’ll make fewer mistakes.A．or B．asC．and D．but23．What is generally accepted is that Chinese were the earliest to play football ___________ the modern rules for football were established by the Europeans.A．when B．whileC．if D．where24．He alway s keeps an eye on shortcomings of his brother’s _________ refusing to admit his own mistakes.A．but B．whileC．although D．though25．I hope you don’t mind me asking, ________ where did you buy those shoes?A．so B．and C．yet D．but26．Do what you have been told, ____ you will be punished.A．and B．butC．or D．after all27．He was about to leave ______ the telephone rang.A．while B．as C．whether D．when28．After reaching the top of the West Hill, we sat around ________.A．exhaustedly and happily B．exhausted and happyC．exhaustedly but happily D．exhausted but happy29．The volcano erupted for the next two days. Many people were buried alive,__________was the city.A．so B．and asC．such D．and so30．Don’t use your mobile phone while charging, ______ you may be shocked b y electricity. A．or B．and C．but D．yet31．The fact has worried many scientists ______ the earth is becoming warmer and warmer these years.A．what B．whichC．that D．though32．I was glad to meet Lydia again, _______ I didn't want to spend all day with her.A．but B．and C．or D．so33．After ten days’ traveling, the couple arrived home, _________.A．tired and delighted B．tired but delightedC．tiredly and delightedly D．tiredly but delightedly34．Tom is very good at science, ________ his brother is fond of literature.A．when B．while C．as D．once35．The young man tried to stop, ________he drove too fast to stop.A．and B．but C．so D．or36．________ Chinese ________ Japanese are Asians.A．Both；and B．Neither；nor C．Neither；or D．Either；or 37．“________, but Jim made the same mistakes again,” complained his mother. A．Although he was told many times B．Having been told many timesC．As he was told many times D．He had been told many times38．He was about to set off________it rained.A．the moment B．when C．while D．as39．You must learn to consult your feelings and your reasons ________ you reach any decision. A．although B．before C．because D．unless40．The mother saw her baby fall to the ground, ________ brought her heart to her mouth. A．it B．and that C．and which D．that【参考答案】一、从属连词1．A【解析】【详解】考查连词。

IP地址练习题题1：现要对C类192.168.10.0网络划分13个子网，求各子网的子网掩码、网络地址、广播地址、以及可容纳的最多主机数。

解析：子网掩码是255.255.255.240；第一个子网的IP地址范围是192.168.10.0~192.168.10.15，则它的网络地址就是192.168.10.0，广播地址是192.168.10.15。

第二个子网的网络地址和广播地址就分别为192.168.10.16和192.168.10.31。

依次类推。

每个子网最多可容纳的主机数是16-2=14个。

题2：一个子网IP地址为10.32.0.0，子网掩码为255.224.0.0的网络，它允许的最大主机地址是什么？解析：10.63.255.254题3：现要IP地址为10.32.0.0，子网掩码为255.224.0.0的子网上再进行子网划分，把它划分成8个子网，求重新划分子网后的子网掩码和各子网的网络地址和广播地址。

解析：重新划分子网后的子网掩码为255.252.0.0。

这8个子网的IP地址范围分别是：10.32.0.0~10.35.255.255，10.36.0.0~10.39.255.255、10.40.0.0~10.43.255.255、10.44.0.0~10.47.255.255、10.48.0.0~10.51.255.255、10.52.0.0~10.55.255.255、10.56.0.0~10.59.255.255、10.60.0.0~10.63.255.255。

各子网的网络地址和广播地址就是上述对应子网IP地址范围中的第一个和最后一个IP地址。

题4：现想对、、、进行子网聚合，求新网络的子网掩码。

解析：新网络的子网掩码为255.255.252.0。

题5：一个公司有五个部门，生产部有120个网络节点，工程部、财务部、市场部、行政部的网络节点数都在30个以内。

现想用一个网络进行划分。

请给出相应的子网方案。

连词练习题(及答案)一、从属连词1．The last time we met each other was_________I was on a business trip in Beijing.A．when B．how C．where D．why2．I will recommend the chain store to ____ is interested in good quality and excellent service. A．whoever B．who C．whomever D．whom3．_______ a lot of hard work and a touch of luck play a part, perseverance is the key to success. A．However B．When C．Whether D．While 4．Learning a foreign language is not easy， and it comes to speaking， it can be more difficult．A．when B．unless C．once D．while5．Ms. Ji had been thinking about what to cook for lunch the whole morning ________ all at once an authentic recipe for stewed eggplants ________ her on her drive home.A．when; stuck B．while; struck C．when; struck D．while; stuck6．_______ he finished his description, I knew it would be years _______ everything got right. A．At the moment, since B．At the moment; beforeC．The moment; since D．The moment; before7．You will never achieve success _______ you keep working hard.A．when B．if C．unless D．because8．He hasn’t got any hobbies—________ you call watching TV a hobby.A．if B．as long as C．unless D．although 9．There was never any time for her to feel happy, ______ lots of people loved her.A．ever since B．now that C．even though D．as if10．He made a mistake, but then he corrected the situation ________ it got worse.A．until B．when C．before D．as11．The meeting didn’t start______ everyone was there.A．because B．until C．why D．if12．Autumn is here. ________ time goes on,it's getting colder and colder.A．As B．With C．Because D．Since13．You’d better conduct the experiment ________ your professor have instructed you; otherwise you may fail to complete it.A．that B．which C．as D．when14．It’s more than half a century ________ my grandfather joined the Party and b ecame a servant to the people.A．when B．that C．since D．as15．________ I can remember, this is the third time we’ve met.A．As soon as B．As long as C．As much as D．As far as16．The manager said he supported the move________ he didn’t think it would make much of a differenceA．so that B．in order that C．now that D．even though 17．Their use was limited by laws, the first of ________ dates back to the fourteenth century. A．where B．which C．that D．when18．______ the fire broke out, all the students were sleeping soundly.A．Because B．In case C．When D．As long as19．______ the man isn’t very rich, he gives a large amount of money to the students every year. A．Though B．Since C．Unless D．If20．There is no doubt ________ man will continue to explore the vast universe in the future，but the rate at which we approach depends on the development of technology.A．whether B．what C．when D．that二、并列连词21．—I hear Susan will go to Beijing by herself.—That’s true her father her mother will go with her.A．both, and B．either, or C．neither, nor 22．【2018·江苏97校联考】Parents should be aware of the fact that children, who are raised on a diet of soap operas and online games, seldom, participate in a variety of activities. A．if never B．if notC．if ever D．if so23．My mother is always warni ng me when I go out, “Don’t get off the bus ________ it is stopping.”A．until B．whileC．before D．after24．The book is now out of print, ______ it can easily be borrowed from libraries.A．and B．forC．so D．but25．—Monica, someone wants you on the phone!—_____ nobody knows I’m in Beijing.A．Or B．SoC．And D．But26．A person may have a good knowledge of one subject, ______ unable to get it over to an audience.A．so B．forC．yet D．or27．I hope you don’t mind me asking, ________ where did you buy those shoes?A．so B．and C．yet D．but28．Calm down. It won’t be long I tell you the good result.A．since B．afterC．when D．before29．—Many students won’t take part in the after-school activities today.— . We have so much homework to do!A．So will I B．So do I C．Neither will I 30．—Jim, are you_______this Saturday?—Oh, sorry. I need to go to the bookshop_______the bank on Saturday.A．convenient; and B．convenient; as well asC．available; with D．available; as well as31．A lie can travel half way around the world ________ the truth is putting on its shoes.A．if B．whileC．unless D．until32．Alice is fond of playing the piano_______Mary is interested in listening to music.A．while B．however C．although D．when33．I was glad to meet Lydia again, _______ I didn't want to spend all day with her.A．but B．and C．or D．so34．Jogging is good exercise ______ it doesn't pollute the air.A．though B．and C．but D．so35．Zhao Wei is ________ a popular singer, ________ a beautiful actress.A．not only, but also B．between, and C．as, as D．not only, as well 36．—Why can't you get used to the life in Beijing?—________ the crowed traffic ________ the high living cost. The only reason is the badly polluted air.A．Not only; but also B．Either; or C．Both; and D．Neither; nor 37．Life isn’t always beautifu l, ________ the struggles make you stronger and the changes make you wiser.A．or B．so C．but D．for38．We did not know you were in trouble at that time, ______we would have given you a hand. A．otherwise B．howeverC．therefore D．though39．—Take a taxi, you won't get the airport in time.—OK, I will. See you!A．instead B．thusC．otherwise D．meanwhile40．__________these messages always seem important at the time, most people can’t really remember them the next day.A．Because B．Unless C．While D．Since【参考答案】一、从属连词1．A【解析】【详解】考查从属连词。

连词练习题(附答案)一、从属连词1．Mother was worried because little Alice was ill, especially ________Father was away in France.A．as B．that C．during D．if2．Learning a foreign language is not easy， and it comes to speaking， it can be more difficult．A．when B．unless C．once D．while3．__________ I like the color of that hat, I don’t like its shape.A．That B．While C．As D．So4．Take a taxi, you'll miss your train.A．and B．if C．otherwise D．but5．I don’t believe we’ve met before, ________I must say you do look familiar.A．given that B．although C．since D．unless6．hings had been tough when he was in school, he graduated from college with the highest honor.A．If B．While C．Because D．As7．— Sorry, Daddy. I am not getting on well with my studies.— Well. ________ you hadn’t wasted so much time playing online games.A．As if B．Even if C．If only D．Only if8．We’ve missed the bus. It looks _________ we’ll have to walk home.A．ever since B．as long as C．even though D．as though 9．Magic shows are interesting ______ the audience does not discover how the tricks are done. A．as long as B．so that C．as if D．ever since 10．The old couple loves the boy ________ he were their own son.A．even if B．unless C．as if D．though11．— Have you heard that Space X sent a Tesla car into space?— Yes. __________ they have achieved is amazing.A．Where B．What C．That D．How12．________ I have a car, I seldom use it because of the traffic jams.A．Although B．If C．As if D．Unless13．I’ve been fond of hiphop music ________ Hiphop Man was shown on TV.A．while B．since C．unless D．until14．She remembered it________ it were yesterday and knew it would haunt her forever.A．as though B．even though C．as soon as D．the moment 15．The reason________ some people pay more attention to their appearance is that they care much more about what other people think of them.A．where B．that C．when D．why16．_________ you try to do something beyond what you have already mastered, you will never grow.A．Once B．If C．Because D．Unless17．He always thinks __________he can do more for the people．A．of how B．how C．of that D．why18．They didn’t start the work ______ their teacher came back.A．until B．while C．as soon as D．if19．________ my head had cleared, my brain was beginning to function much better.A．Now that B．Although C．Due to D．Despite20．________there was no solid evidence, most people thought he was guilty.A．Because B．While C．As D．Unless二、并列连词21．Alice is fond of playing the piano_______Mary is interested in listening to music. A．while B．however C．although D．when22．The book is now out of print, ______ it can easily be borrowed from libraries.A．and B．forC．so D．but23．—Monica, someone wants you on the phone!—_____ nobody knows I’m in Beijing.A．Or B．SoC．And D．But24．The largest collection ever found in England was one of about 200,000 silver pennies, and ______ were over 600 years old.A．all of them B．all of whichC．all of whom D．they all25．He was about to leave ______ the telephone rang.A．while B．as C．whether D．when 26．Jenny feels a blankness ________ she once felt a sense of purpose and excitement. A．unless B．where C．as D．since27．I say Tom is a smart boy, he still needs to work hard to achieve his goal.A．Because B．When C．As D．While28．__________these messages always seem important at the time, most people can’t really remember them the next day.A．Because B．Unless C．While D．Since 29．—Mum, I broke Dad’s sunglasses this morning.—You need to make an apology for your fault, ________ you will regret.A．and B．orC．but D．for30．Actually, our hobbies vary a lot—I like outdoor activities, _________ square dance is mywife’s preference.A．although B．when C．while D．as31．— Someone wants you on the phone.— ________ nobody knows I am here.A．Although B．AndC．So D．But32．Last night, I was packing my bag and texting a message to my boss ________ I heard a cry for help from outside the office.A．when B．as C．before D．while33．Some people never seem to put on weight________ others are always on a diet.A．while B．or C．since D．for34．These activities can ________help them gain more skills, ________teach them to care about others.A．both; and B．not only; but also C．either; or D．neither; nor 35．– Did you remember to give Tom the key to the office?– Yes. I gave it to him ________ I saw him.A．as long as B．once C．the moment D．while36．Not only __________ a promise, but also __________ it.A．did he make; he kept B．he made; he keptC．did he make; did he keep D．he made; did he keep37．—I’m planning to climb Mount Huang this summer. Would you like to come along?—Wow! That would be exciting ________ challeng ing. I’m in!A．as well as B．as good as C．as long as D．as far as38．We did not know you were in trouble at that time, ______we would have given you a hand. A．otherwise B．howeverC．therefore D．though39．Tom is really good at science, his brother is a natural artist.A．while B．becauseC．for D．as40．Going to the movies is good， I really only like listening to music.A．and B．but C．so D．or【参考答案】一、从属连词1．A【解析】【详解】考查状语从句。

光传输练习题库含答案一、单选题（共40题，每题1分，共40分）1、下列网络结构中，网络生存性最好的是( )A、A- 环形B、B-线形C、C-星形D、D-树形正确答案：A2、在障碍级别方面，因配线光缆损坏造成EPON系统一半以上用户阻断的为（）A、A- 全阻障碍B、B-严重障碍C、C-一般障碍D、D-中级障碍正确答案：B3、ODU2在OTN中代表的速率为()A、2.5GB、10GC、40GD、100G正确答案：B4、在光纤接头标注中，如“SC/PC”，“/”前半部分的SC表示连接器型号，“/”后半部分的PC指什么？（)A、A- 光纤的类型B、B-光纤的制作工艺C、C-光纤接头截面工艺D、D-连接器制作工艺正确答案：C5、严重误码秒：即1秒钟内的误码率劣于门限值，其门限值是（）。

A、A： 1X10-6B、B：1X10-10C、C：1X10-8D、D：1X10-3正确答案：D6、FTTX网络，ONU与OLT连接使用的光纤类型为（）A、A- 单模B、B-双模C、C-多模正确答案：A7、架空光缆与街道平行最小垂直净距为（）A、5mB、4.5m；C、3m；D、4m；正确答案：B8、在工程中，皱纹钢带铠装光缆适用于（）。

A、A管道B、B架空C、C直埋D、D一般河流、坡度大的地段正确答案：C9、架空线路维护质量要求拉线对位准确、地锚出土长度不大于（）米，各种拉线不得有锈蚀、松驰现象。

拉线上不得附有其它杂物。

A、0.1B、0.3C、0.8D、0.5正确答案：D10、正常光缆割接完成后，开放高速环网DWDM系统对应段损耗值在与割接前比较，当差值在（）dB以下时，可认为割接完成。

A、A 5B、B 2C、C 1D、D 0.5正确答案：D11、单模光纤在1310nm窗口的衰耗约 0.35dB/km，在1550nm窗口的衰耗可低达（） dB/km。

A、0.20C、0.30D、D. 0.35正确答案：A12、实际工程中,如果某根光缆突然被打坏,通常调换掉的这段光缆只有几百米,这时需要你对新敷设的这根短光缆进行盘测,而手头并不具备1-2km长的标准光纤,你该怎样较准确的测出这段光缆的衰减系数。

网络互联技术习题1.RIP 的路由器的最大跳跃记数是多少dA.6B.16C.12D.152.用户需要在一个C类地址中划分子网，其中一个子网的最大主机数是16，如果要得到最多的子网数亮，子网掩吗应该是：dA.255.255.255.22B.255.255.255.192C.255.255.255.248D.255.255.255.2403.某单位搭建了一个有六个子网，C类IP地址的网络要正确配置该网络应该使用的子网掩吗是： aA.255.255.255.224B.255.255.255.192C.255.255.255.254D.255.255.255.2404.哪中协议是距离矢量路由协议，同时属于内部网官协议 cA.OSPFB.NLSPC.RIPD.BGP-45.被路由的协议 bBEUIB.TCP/IPC.IPX/SPX6.防火墙的功能是什么？bA，过滤MAC地址层B，过滤网络地址层C，保护硬件资源D，减少内部网络的活动7.关于VLAN，以下描述正确的是_______________。

ACFGA、每个VLAN类似一个物理网段B、一个VLAN只能在一个交换机上划分C、干道（Trunk）携载多个VLAN的信息D、VLAN不能由管理员静态（人工）划分E、VLAN可按主机名动态划分F、VLAN可按IP地址动态划分G、VLAN可按MAC地址动态划分8.有一个C类网络，要分8个子网，每个子网有30台主机，应该选择的子网掩码bA．255.255.255.0B. 255.255.255.224C.255.255.255.240d.255.255.255.2529.网络设备用什么管理协议？bA．NMS B SNMP C.HTTP D．SMTP10.在OSPF中，_____类型的LSA是由ABR产生，描述ABR和其某个本地区域各内部路由器之间的链路以下内容为程序代码:A。

类型1 B。

类型2 C。

类型3，4 D。

类型5 （答案：C）11、VLAN的特点是_____________。

小学数学《图形的分割与拼接》练习题（含答案）把一个几何图形按某种要求分成几个图形，就叫做图形的分割．反过来，按一定的要求也可以把几个图形拼成一个完美的图形，就叫做图形的拼合．将一个或者多个图形先分割开，再拼成一种指定的图形，则叫做图形的剪拼．我们在图形的分割、拼合和剪拼的过程中，都要结合所提供的图形特点来思考．如果把一个图形分割成若干个大小、形状相等的部分，那么就要想办法找图形的对称点，把图形先分少，再分多．图形中，如果有数量方面的要求，可以先从数量入手，找出平分后每块上所含数量的多少，再结合数量来分割图形．如果是要把几个图形拼合成一个大图形，要特别注意每条边的长度，把相等的边长拼合在一起，先拼少的，再拼多的．如果是剪拼图形，要抓住“剪、拼前后图形的面积相等”这个关键，根据已知条件和图形的特点，通过分析推理和必要的计算，确定剪拼的方法．（一）图形的分割【例1】（★★★）如右图所示是由三个正方形组成的图形，请把它分成大小、形状都相同的四个图形？→→分析：要求把原来三个正方形分成四个大小、形状都相同的四个图形，先不考虑形状，大小相同也就是面积相等，也就是把整个图形的面积分成四份，分割后的每一部分占一份，可以考虑把每一个正方形的面积分成四份，再把三个正方形中的每一个小正方形合成要求的图形，如右上图所示.[拓展]把如右图这样由五个正方形组成的图形，分成四块大小、形状都相同的图形→→分析：从面积考虑，把整个图形的面积分成四份，分割后的每一部分占一份.正方形，则可把每个正方形分成四个面积相等的小正方形，每块图形应有五个这样的小正方形，如右上图所示.[巩固]右图是由五个正方形组成的图形．把它分成形状、大小都相同的四个图形，应怎样分?分析：如果不考虑分成的四个图形的形状，只考虑它们的面积，这就要求把原来五个正方形分成四个面积相等的图形，每个图形的面积应是1个多正方形．我们把每个正方形各分成四个面积相等的小正方形，分成的每块图形应有五个这样的小正方形．根据图形的对称性，我们很快就能得到如右上图的分法.【例2】（★★★★）把任意一个三角形分成面积相等的4个小三角形，有许多种分法．请你画出4种不同的分法．分析：根据等底等高的三角形面积相等这一结论，只要把原三角形分成4个等底等高的小三角形，它们的面积必定相等．而要得到这4个等底等高的小三角形，只需把原三角形的某条边四等分，再将各分点与这边相对的顶点连接起来就行了.根据上面的分析，可得如左上图所示的三种分法．又因为4＝l×4＝2×2，所以，如果我们把每一个小三角形的面积看做1，那么1×4就可以视为把三角形的面积直接分成4等份，即分成4个面积为1的小三角形；而2×2可以视为先把原三角形分成两等份，再把每一份分别分成两等份．根据前面的分析，在每次等分时，都要想办法找等底等高的三角形．根据上面的分析，又可以得到如右上图的另两种分法．[前铺] 把任意一个三角形分成面积相等的2个小三角形，有许多种分法．请你画出4种不同的分法．分析：根据等底等高的三角形面积相等这一结论，只要把原三角形分成2个等底等高的小三角形，它们的面积必定相等．而要得到这2个等底等高的小三角形，只需找出原三角形的某条边的中点与这边相对的顶点连接起来就行了.根据上面的分析，可得如下图所示的三种分法．[拓展]怎样把一个等边三角形分别分成8块和9块形状、大小都一样的三角形.→分析：（1）分成8块的方法是：先取各边的中点并把它们连接起来，得到4个大小、形状相同的三角形，然后再把每一个三角形分成一半，得到如左上图所示的图形.（2）分成9块的方法是：先把每边三等分，然后再把分点彼此连接起来，得到加上右上图所示的符合条件的图形.【例3】（★★★★）如下图所示，请将这个正方形分切成两块，使得两块的形状、大小都相同，并且每一块都含有学而思奥数五个字.→图1 图2分析：图中有相同汉字挨在一起的情况，肯定要从它们之间切开（图1），因此，首先要在它们之间划出切分线.因为要将这个正方形切开成两块形状和大小都一样的图形，所以其中一块绕中心点旋转180°必定与另一块重合.要是把切分线也绕中心点旋转180°就可得到一些新的切分线（图2）.这就为我们解决问题提供了线索，本题的两种解法如上图所示.[拓展] 如右图所示的正方形是由36个小正方格组成的.如图那样放着4颗黑子，4颗白子，现在要把它切割成形状、大小都相同的四块，并使每一块中都有一颗黑子和一颗白子.试问如何切割？分析：首先在相同颜色的棋子之间划出切分线，以中心旋转90°、180°、270°之后，得一些新的切分线，同时考虑到每块包含有一颗黑子和一颗白子的要求，以及每一块面积应该是36÷4=9，即含有9个小正方格，先找到符合要求的一块后，让它绕中心旋转90°、180°、270°便得到其他三块，如右上图.（二）图形的拼合【例4】（★★★）将方格纸剪成面积是4的图形，形状只有七种，如下图所示．其中有哪几种自身可以拼成面积是16的正方形?分析：面积是16的正方形，其边长等于4，用图形(5)和(7)显然能拼成边长是4的正方形(如左上图所示)．用图形(1)、(2)和(6)也能拼成边长为4的正方形(如右上图所示)．通过观察与试验，无法用所给图中的(3)和(4)拼成题目要求的正方形．因此，用所给图中的七种图形，共可以拼成5种面积是16的正方形．[巩固]下面哪些图形自身用4次就能拼成一个正方形？分析：用4块图（4）和图（5）那样的图形显然能够拼成一个大正方形．其实用图（1）、图（2）、图（3）也能拼成一个大正方形，拼法见右上图．【例5】（★★★★）用6个完全一样的等腰直角三角形拼图，要求边与边完全重合．你能拼出几种图形?把它们画出来．分析：建议用等腰直角三角板，把不同的边进行重合，不要漏掉旋转重合，或者准备一些等腰直角三角形的纸片，由学生拼接后贴到黑板上，见下图[前铺]用3个等腰直角三角形拼图，要求边与边完全重合，能拼出几种图形?分析： 这种类型的题需要学生亲自操作，建议教师准备材料与学生互动。