【单选题】
20.M7130型平面磨床中,电磁吸盘退磁不好使工件取下困难,但退磁电路正常,退磁电压也正常,则需要检查和调整___。
A. 退磁功率
B. 退磁频率
C. 退磁电流
D. 退磁时间
查看试卷,进入试卷练习
微信扫一扫,开始刷题

答案
D
解析
暂无解析
相关试题
【单选题】
35.C6150型车床控制电路中的中间继电器KAl和KA2常闭触点故障时会造成___。
A. 主轴无制动
B. 主轴电动机不能启动
C. 润滑油泵电动机不能启动
D. 冷却液电动机不能启动
【单选题】
37.C6150型车床其他正常,而主轴无制动时,应重点检修___。
A. 电源进线开关
B. 接触器KMl和KM2的常闭触点
C. 控制变压器TC
D. 中间继电器KAl和KA2的常闭触点1
【单选题】
39.C6150型车床主电路有电,控制电路不能工作时,应首先检修___。
A. 电源进线开关
B. 接触器KMl或KM2
C. 控制变压器TC
D. 三位置自动复位开关SAI
【单选题】
43.Z3040型摇臂钻床中的主轴电动机,___。
A. 由接触器KMl控制单向旋转
B. 由接触器KMl和KM2控制正反转
C. 由接触器KMl控制点动工作
D. 由接触器KMl和KM2控制点动正反转
【单选题】
47.Z3040型摇臂钻床中的摇臂升降电动机,___。
A. 由接触器KMl控制单向旋转
B. 由接触器KM2和KM3控制点动正反转
C. 由接触器KM2控制点动工作
D. 由接触器KMl和KM2控制自动往返工作
【单选题】
51.Z3040型摇臂钻床中的液压泵电动机,___。
A. 由接触器KMl控制单向旋转
B. 由接触器KiVl2和KM3控制点动正反转
C. 由接触器KM4和KM5控制实行正反转
D. 由接触器KMl和KM2控制自动往返工作
【单选题】
52.Z3040型摇臂钻床的液压泵电动机由按钮、行程开关、时间继电器和接触器等构成的___控制电路来控制。
A. 单向启动停止
B. 自动往返
C. 正反转短时
D. 减压启动
【单选题】
60.Z3040型摇臂钻床中摇臂不能升降的原因是摇臂松开后KM2回路不通时,应___。
A. 调整行程开关SQ2位置
B. 重接电源相序
C. 更换液压泵
D. 调整速度继电器位置
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