【单选题】
已知活塞有效工作面积为0．008 m2，外界负载为9 720 N，则液压缸的工作压力为___
A. 12．15×104Pa
B. 12．15×105Pa
C. 8．2×10-7Pa
D. 8．2×10-6Pa
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相关试题
【单选题】
在测量过程中，由一些无法控制的因素造成的误差称为___。
A. 随机误差
B. 系统误差
C. 粗大误差
D. 偶然误差
【单选题】
通过测量某一量值，并借助已知函数关系计算出需要的测量数据的测量方法叫___
A. 直接测量
B. 间接测量
C. 函数计算
D. 误差换算
【单选题】
用量具测出零件的弓高和弦长，通过公式计算出直径的测量方法叫___。
A. 直接测量
B. 间接测量
C. 随机测量
D. 系统测量
【单选题】
两孔的中心距一般都用___测量法测量。
【单选题】
畸形工件需多次划线时，为保证加工质量必须做到___。
A. 安装方法一致
B. 划线方法一致
C. 划线基准统一
D. 借料方法相同
【单选题】
箱体加工时，是用箱体的___来找正的。
【单选题】
当麻花钻顶角小于118。时，两主切削刃呈___。
A. 直线形
B. 曲线形
C. 外凸形
D. 内凹形
【单选题】
当麻花钻顶角大于118。时，两主切削刃呈___。
A. 直线形
B. 曲线形
C. 外凸形
D. 内凹形
【单选题】
目测麻花钻___，可以判断出麻花钻后角的大小。
A. 横刃斜角
B. 顶角
C. 前角
D. 钻心角
【单选题】
麻花钻主切削刃上各点的前角和后角是不等的，就外缘处来说___。
A. 前角最大，后角最小
B. 前角最小，后角最大
C. 前角最大，后角最大
D. 前角最小，后角最小
【单选题】
修磨钻铸铁的群钻，主要是磨出___。
A. 三尖
B. 七刃
C. 分屑槽
D. 双重项角
【单选题】
钻黄铜或青铜，主要是解决钻头的___。
【单选题】
修磨薄板群钻主要是将两主切削刃磨成圆弧形，钻尖磨低，直到形成___。
A. 三尖
B. 分屑槽
C. 两顶角
D. 外刃
【单选题】
在毛坯上扩孔主要解决的是___的问题。
A. 切削深度
B. 定心难
C. 进给量
D. 转速选定
【单选题】
普通麻花钻扩孔切削时容易产生___。
A. 进给困难
B. 扎刀
C. 加工效率低
D. 加工质量差
【单选题】
在矿ø20mm的底孔上扩ø40mm的孔，则切削深度为___。
A. 5 mm
B. 10mm
C. 15mm
D. 20mm
【单选题】
在口ø20mm的底孔上扩ø45mm的孔，则切削深度为___.
A. 5mm
B. 7．5mm
C. 12．5mm
D. 15mm
【单选题】
旋转零件的重心不在旋转轴线上，当其旋转时只产生垂直旋转中心的离心力，此种现象称为___。
A. 静平衡
B. 静不平衡
C. 动平衡
D. 动不平衡
【单选题】
旋转零件的重心在旋转轴线上，当其旋转时有不平衡力矩产生，此种现象称为___。
A. 静平衡
B. 静不平衡
C. 动不平衡
D. 动平衡
【单选题】
可以独立进行装配的部件称为___。
A. 装配系统
B. 装配基准
C. 装配单元
D. 组件
【单选题】
用测力扳手拧工件目的是为了___。
A. 防松
B. 控制拧紧力矩
C. 保证正确连接
D. 提高装配效率
【单选题】
弹簧垫圈上开出斜口目的是为了___。
A. 增大预紧力
B. 产生弹力
C. 防止螺母回转
D. 增大摩擦力
【单选题】
圆锥面过盈连接是利用包容件与被包容件的___而获得过盈量的。
A. 相对轴向位移
B. 过盈值的大小
C. 配合性质
D. 装配方法
【单选题】
滚动轴承预紧的根本目的是___。
A. 消除游隙
B. 减少变形
C. 增大载荷
D. 提高轴承工作时的刚度和旋转精度
【单选题】
蜗杆传动机构正确啮合，蜗轮轮齿上的接触斑点位置应在___。
A. 齿面中部
B. 齿面端部
C. 齿面中部稍偏蜗杆旋出方向
D. 齿面中部稍偏蜗杆旋入方向
【单选题】
当齿轮的接触斑点位置正确，而接触面太小时，是由于___所致。
A. 侧隙太大
B. 中心距偏大
C. 中心距偏小
D. 齿形误差太大
【单选题】
齿轮安装中心距误差不仅影响齿轮的接触位置，而且影响___。
A. 齿侧间隙
B. 接触面
C. 传动比
D. 传动效率
【单选题】
两啮合齿轮___，会产生同向偏接触。
A. 中心距太大
B. 中心距太小
C. 安装轴线不平行
D. 径向跳动
【单选题】
82两啮合齿轮接触面的大小，是根据齿轮的___要求而定的。
A. 接触精度
B. 齿侧间隙
C. 运动精度
D. 转速高低
【单选题】
螺纹连接属于___。
A. 可拆的活动连接
B. 不可拆的固定连接
C. 可拆的固定连接
D. 不可拆的活动连接
【单选题】
楔键连接属于___。
A. 可拆的活动连接
B. 不可拆的固定连接
C. 可拆的固定连接
D. 不可拆的活动连接
【单选题】
销连接属于___。
A. 可拆的活动连接
B. 不可拆的固定连接
C. 可拆的固定连接
D. 不可拆的活动连接
【单选题】
操作简便，生产效率高的装配方法是___。
A. 完全互换法
B. 选配法
C. 调整法
D. 修配法
【单选题】
采用分组选配法装配，配合精度的高低取决于___。
A. 零件的加工精度
B. 装配方法
C. 装配过程
D. 分组数
【单选题】
一般来说，流水线、自动线装配都采用___。
A. 完全互换法
B. 选配法
C. 调整法
D. 修配法
【单选题】
部件装配是从___开始的。
A. 零件
B. 基准零件
C. 装配单元
D. 基准部件
【单选题】
根据装配精度合理分配各组成环公差的过程，叫___。
A. 工艺分析
B. 尺寸计算
C. 解尺寸链
D. 精度保证
【单选题】
封闭环的公差等于___。
A. 各组成环公差之和
B. 各组成环公差之差
C. 减环公差之和
D. 增环公差之和
【单选题】
修配法解尺寸链的主要任务是确定___在加工时的实际尺寸。
A. 增环
B. 减环
C. 封闭环
D. 修配环
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10. —I’m going to Flower Bookstore. Could you tell me ______?
— Sorry, I don’t know. I’m new here.
A. where it is B. where was it C. where is it D. where it was
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11. How do you like the dishes, Eric?
— Fantastic! Nothing tastes ________.
A. nice B. better C. terrible D. worse
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12. ______ Lin Feng has to work late, she always wears a smile on her face.
A. Because B. If C. Until D. Though
【单选题】
13.You can save money _______ you buy cheaper things.
A. before B. unless C. if D. until
【单选题】
14. We will have a _________ holiday after the exam．
A. two-month B. two month’s C. two month D. two-months
【单选题】
15. —We will build an underground in Xuzhou before 2015．
— Wow, _______! Will it pass our place?
A. what an excited news B. how excited the news is
C. what exciting news D. how exciting
【单选题】
16. — Emily, here’s a dictionary．I hope it will help you in some way．
— Thank you．It’s ________ what I need．
A. almost B. still C. only D. just
【单选题】
17. —Oh．I’m hungry．Mum, can I have the hamburger on the plate?
—No．It tastes ．
A. terribly B. terrible C. good D. well
【单选题】
18. —We can invite our teachers to the farewell party next Saturday.
—Yes, ______? I’ll call them at once.
A. what for B. what C. why not D. why
【单选题】
19.You can ________ ask the old man to move away to any other place because he has lived ________ here for at least sixty years．
A. hardly; alone B. hard; alone
C. hardly; lonely D. hardly; lonely
【单选题】
20.—I’m going back to see my grandparents this weekend．
—________．
A. It’s very nice of you B. You’d better hurry
C. Say goodbye to them D. Give my best wishes to them
【单选题】
21.—Why not take ____ umbrella with the sign “Made in China”? It is useful.
—What _______ good advice it is!
A. an; a B. a; a C. an; \ D. \; a
【单选题】
22. —Do you know the boy________ is sitting next to Peter?
— Yes. He is Peter’s friend. They are celebrating his ________ birthday.
A. who; ninth B. that; ninth C. /; ninth D. which; ninth
【单选题】
23. It was dark, ______ I couldnt see what was happening.
A. or B. though C. but D. so
【单选题】
24.—You can use MSN to talk with Vivien on the Internet.
—I know. But can you tell me ________?
A. what I can use it B. when I can use it
C. why can I use it D. how can I use it
【单选题】
25. _______ are you going to the School Uniform Exhibition, Amy ?
To learn about different styles of school uniform.
A. What B. Where C. Which D. Why
【单选题】
( ) 26. Where does the writer of "The little Prince" come from?
A．England． B．France． C．America． D．China．
【单选题】
( ) 27. What does the prince do after the fox tells him a secret?
A．He cares more about a flower and a sheep．
B．He meets many more strange adults on other planets．
C．He realizes his love for the rose and he goes back to his planet．
D．He discovers interesting things such as a snake, other roses and a fox
【单选题】
( ) 28. What does "The little Prince" mainly talk about? It' s about _________．
A．the adult world B．the planet B -612
C．a rose and a fox D．the adventure of a young prince
【单选题】
( ) 29. What is the writer's main purpose（目的）in writing this passage？
A．To tell the readers his life story．
B．To tell people what kind of person his father was．
C．To tell the readers what present he got from his father．
D． To let people know how poor he was．
【单选题】
( ) 30. Why did the father not ask his son not to do this and do that？
A．Because he felt quite confident of his son．
B．Because he was born from a poor family．
C．Because he was a man of few words．
D．Because he didn't want to be much too strict with his son．
【单选题】
( ) 31. What would someone learn from this passage？
A．How to live by oneself． B．How to stand on one's own feet．
C．What a good father should do． D．What the self-important is like．
【单选题】
( ) 32. What may be the proper Chinese for the underlined part in the passage？
A．闲暇时光 B．学费 C．精神空虚 D．经济不足
【单选题】
( ) 33. Why did Natalie Smith pay for the six cars behind her?
A. She had seven tickets.
B. She hoped to please others.
C. She knew the car drivers well.
D. She wanted to show kindness.
【单选题】
( ) 34. Judy Foreman copied down the phrase because she ___ .
A. thought it was beautifully written
B. wanted to know what it really meant
C. decided to write it on a warehouse wall
D. wanted her husband to put it up in the classroom
【单选题】
( ) 35. Who came up with the phrase according to the passage?
A. Judy Foreman. B. Natalie Smith. C. Anne Herbert D. Alice Johnson.
【单选题】
( ) 36. What can we infer from the last paragraph?
A. People should practice random kindness to those in need.
B. People who receive kindness are likely to offer it to others.
C. People should practice random kindness to strangers they meet.
D. People who receive kindness are likely to pay it back to the giver.
【单选题】
( ) 37.The greatest river for navigation is ___________.
A. the Nile B. the Amazon C. the Mekong D. the Mississippi
【单选题】
( ) 38. From a dam, people can use the water for ___________.
A. keeping the rivers clean B. only making electricity
C. irrigation and making electricity D. washing clothes
【单选题】
( ) 39. The water in the river is polluted because of _____________.
A. people's drinking water too much B. people's swimming in the river too much
C. chemicals and other materials D. people's building a dam across a river
【单选题】
( ) 40. The best title of the passage is ___________.
A. Rivers in Cities B. The importance of Rivers
C. Transportation D. Natural Resources
