【单选题】
冷冻润滑油具有___的绝缘性和击穿电压
A. 一般
B. 良好
C. 较差
D. 特殊
查看试卷,进入试卷练习
微信扫一扫,开始刷题
答案
B
解析
暂无解析
相关试题
【单选题】
绝对压力是指设备内部或某处真实压力,等于表压力与当地大气压力___
A. 之和
B. 之差
C. 乘积
D. 之比
【单选题】
电风扇在额定电压下连续工作一小时,测量绝缘电阻不小于___兆欧
A. 0.1
B. 0.5
C. 1
D. 2
【单选题】
流体在管道中流动,通过阀门,孔板等设备时,由于局部阻力,使流体的压力___,这种现象就称为节流现象
A. 升高
B. 降低
C. 保持不变
D. 平衡
【单选题】
防滑器速度传感器软管最小弯曲半径为___mm
A. 30
B. 50
C. 70
D. 90
【单选题】
液体制冷剂通过节流阀的过程是一个节流过程,其节流前后焓值___
A. 增加
B. 减少
C. 不变
D. 改变
【单选题】
KTA-1150型柴油机本身冷却容积为___L
A. 20
B. 25
C. 30
D. 35
【单选题】
液体表面和内部同时发生剧烈的___现象,称为沸腾
A. 翻滚
B. 波动
C. 汽化
D. 蒸发
【单选题】
下列属于车电机具的是___
A. 发电机
B. 排气扇
C. 播音配电盘
D. 电力连接器
【单选题】
液体的温度越高,表面越大,蒸发就会___
A. 停止
B. 越慢
C. 越快
D. 改变
【单选题】
KP-2A型控制箱的静态正常激磁电压为___伏特
A. 0.4-0.65
B. 0.15-0.35
C. 0.7-0.9
D. 0
【单选题】
物质从固态直接转变为___的过程叫升华
A. 气态
B. 固态
C. 液态
D. 水
【单选题】
电扇的中修周期规定为___年
A. 1.5
B. 1
C. 9个月
D. 6个月
【单选题】
根据压缩机的工作原理,压缩机可分为___型和速度型两种
A. 面积
B. 体积
C. 容积
D. 复合
【单选题】
低压电器是指工作在交流___伏特以下电路的电器
A. 400
B. 380
C. 220
D. 1000
【单选题】
25T型客车的蓄电池组容量应不小于___
A. 315A•h
B. 450 A•h
C. 120 A•h
D. 100 A•h
【单选题】
BY-2型逆变器在恒压60v运用2h,其三极管双管对比温差不大于___度
A. 5
B. 10
C. 20
D. 30
【单选题】
压缩机在制冷系统中用来压缩和输送制冷剂___
A. 液体
B. 气体
C. 蒸气
D. 能量
【单选题】
25T型空调客车的一辆车上共安装___个防滑装置的速度传感器
A. 1
B. 2
C. 4
D. 8
【单选题】
制冷剂汽化吸收大量的汽化潜热,把空气的___带走
A. 冷气
B. 热气
C. 热量
D. 湿气
【单选题】
列车在始发前___,须进行预冷作业
A. 10MIN
B. 30MIN
C. 1H
D. 1.5H
【单选题】
大修后,蓄电池容量应为额定容量的___以上
A. 75%
B. 80%
C. 90%
D. 95%
【单选题】
单元式空调机组控制柜中修周期为___年
A. 1
B. 1.5
C. 2
D. 6
【单选题】
配线绝缘电阻单车母车应符合___兆欧
A. 0.05
B. 0.02
C. 0.2
D. 0.1
【单选题】
下列属于低压配电电器的是___
A. 手控开关
B. 自动开关
C. 主电器
D. 继电器
【单选题】
客车车体配线段修后,墙板引出线的支线截换时须留有___mm以上的余量
A. 80
B. 100
C. 150
D. 200
【单选题】
装有毛细管的制冷系统,在压缩机停机后,需要___min才能再次启动
A. 1-2
B. 2-3
C. 3-5
D. 5min以上
【单选题】
三极管基本放大电路有___种基本接线方式
A. 1
B. 2
C. 3
D. 4
【单选题】
晶体管断态重复峰值电压的数值,规定比正向转折电压小___V
A. 100
B. 120
C. 150
D. 200
【单选题】
在电源频率不变的情况下,三相感应电动机的转矩和___成正比
A. I
B. I的二次方
C. U
D. U的二次方
【单选题】
碱性蓄电池的大修周期是___年
A. 4
B. 6
C. 12
D. 18
【单选题】
利用熔体熔化作用而切断电路的保护电器叫___
A. 自动开关
B. 组合开关
C. 闸刀开关
D. 熔断器
【单选题】
段修后,蓄电池容量应为额定容量的___以上
A. 60%
B. 70%
C. 80%
D. 90%
【单选题】
容量在___W以上的交流电动机一般采用降压启动
A. 4000
B. 5000
C. 6000
D. 7000
【单选题】
安装电子防滑器的速度传感器时,其软管部分的最大弯曲半径为___MM
A. 50
B. 80
C. 110
D. 140
【单选题】
空调列车电力连接线的长度一般为___mm
A. 1400-1500
B. 1500-1600
C. 1600-1700
D. 1700-1800
【单选题】
客车燃煤取暖锅炉,在点火运用时锅炉内的水温不得超过___℃
A. 85
B. 95
C. 90
D. 100
【单选题】
KP-2A型控制箱中的D7断路时___
A. 发电机不发电
B. 电压失控
C. 误动作
D. 正常
【单选题】
空调装置电气部件与壳的绝缘电阻应大于___兆欧
A. 0.5
B. 1
C. 2
D. 2.4
【单选题】
稳压接到电源上,必须串联一个___
A. 二极管
B. 三极管
C. 电容器
D. 电阻
【单选题】
只要控制基极___,即可使三极管处于截止状态
A. 电压
B. 电流
C. 电阻
D. 电容
推荐试题
【单选题】
Tom is a book lover. ______ likes reading very much. A. He B. She C. You D. It
A. A
B. B
C. C
D. D
【单选题】
—May I listen to the music here, Mr. White? —Sorry, you’d better it like that. A. not to do B. not do to C. dont do D. not do
A. A
B. B
C. C
D. D
【单选题】
3.—Did you have a good time at Lauras birthday party? — Yes, indeed. Its several years ________ I enjoyed myself so much. A. when B. before C. since D. that
A. A
B. B
C. C
D. D
【单选题】
4. —___________ is the Summer Palace from here? About three kilometers away. You can take the No. 35 bus. A. How long B. How far C. How often D. How much
A. A
B. B
C. C
D. D
【单选题】
5. I was looking for a birthday gift for my mother, but I couldnt find ______ suitable. A. anything B. something C. nothing D. everything
A. A
B. B
C. C
D. D
【单选题】
6. A friend of my ____ and I are going to visit_______ next week. A. father; Browns B. father's; Browns C. father; the Browns D. father's; the Browns
A. A
B. B
C. C
D. D
【单选题】
7. She ______ very hard since she came to our school. A. studies B. has studied C. is studying D. studied
A. A
B. B
C. C
D. D
【单选题】
8. — Who will send you to the new school, your mom or your dad? — _______. Ill go there by myself. A. Both B. Either C. Neither D. None
A. A
B. B
C. C
D. D
【单选题】
9.—Well do what we can ____English well this term. —It’s high time for you to work hard. A. study  B.to study  C. be studied   D. be studying
A. A
B. B
C. C
D. D
【单选题】
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
A. A
B. B
C. C
D. D
【单选题】
11. How do you like the dishes, Eric? — Fantastic! Nothing tastes ________. A. nice B. better C. terrible D. worse
A. A
B. B
C. C
D. D
【单选题】
12. ______ Lin Feng has to work late, she always wears a smile on her face. A. Because B. If C. Until D. Though
A. A
B. B
C. C
D. D
【单选题】
13.You can save money _______ you buy cheaper things. A. before B. unless C. if D. until
A. A
B. B
C. C
D. D
【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
A. A
B. B
C. C
D. D
【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
A. A
B. B
C. C
D. D
【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
A. A
B. B
C. C
D. D
【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
A. A
B. B
C. C
D. D
【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
A. A
B. B
C. C
D. D
【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
A. A
B. B
C. C
D. D
【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
A. A
B. B
C. C
D. D
【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
A. A
B. B
C. C
D. D
【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
A. A
B. B
C. C
D. D
【单选题】
23. It was dark, ______ I couldnt see what was happening. A. or B. though C. but D. so
A. A
B. B
C. C
D. D
【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
A. A
B. B
C. C
D. D
【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
A. A
B. B
C. C
D. D
【单选题】
( ) 26. Where does the writer of "The little Prince" come from? A.England. B.France. C.America. D.China.
A. A
B. B
C. C
D. D
【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
A. A
B. B
C. C
D. D
【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
A. A
B. B
C. C
D. D
【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.
A. A
B. B
C. C
D. D
【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.
A. A
B. B
C. C
D. D
【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.
A. A
B. B
C. C
D. D
【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
A. A
B. B
C. C
D. D
【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.
A. A
B. B
C. C
D. D
【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
A. A
B. B
C. C
D. D
【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.
A. A
B. B
C. C
D. S
【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.
A. A
B. B
C. C
D. D
【单选题】
( ) 37.The greatest river for navigation is ___________. A. the Nile B. the Amazon C. the Mekong D. the Mississippi
A. A
B. B
C. C
D. D
【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
A. A
B. B
C. C
D. D
【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
A. A
B. B
C. C
D. D
【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
A. A
B. B
C. C
D. D