【判断题】
狭义上,重大危险源是指可能导致重大事故发生的危险源。
查看试卷，进入试卷练习
微信扫一扫，开始刷题
相关试题
【判断题】
由于电弧的温度极高(中心温度可达6000℃～1000℃),可使其周围的金属熔化、蒸发并飞溅到皮肤表层而使皮肤金属化。
【判断题】
MIG焊适用于铝及铝合金、不锈钢等材料中、厚板焊接。
【判断题】
手工钨极氩弧焊用的填充金属应是直棒(条）。
【判断题】
生活中常用的不锈钢大部分是马氏体不锈钢。
【判断题】
受强烈紫外线的短时间照射,眼睛可以致病。潜伏期一般在半小时至24小时,多数在受照射后4～12小时发病。
【判断题】
焊割炬的喷嘴发生堵塞时,应将喷咀拆下,用通针从内向外捅。
【判断题】
焊接不同材料时,对氩气的纯度要求相同。
【判断题】
在大电流焊接时,增大锥角可避免尖端过热熔化,减少损耗,并防止电弧往上扩展而影响阴极斑点的稳定性。
【判断题】
低碳钢焊接时,由于焊接高温的影响,晶粒长大快,碳化物容易在晶界上积聚、长大,使焊缝脆弱,焊接接头强度降低。
【判断题】
焊接车间焊工作业面积不应该小于4m²,地面应基本干燥。
【判断题】
碳弧刨割条操作时其电弧必须达到一定的喷射能力,才能除去熔化金属。
【判断题】
直流正接时,焊件接直流弧焊机的正极,焊条接负极。
【判断题】
通过人体的电流越大,致命的危险性就越小。
【判断题】
金属材料的强度越高,则抵抗变形和断裂的能力越大。
【判断题】
单相触电时加在人身上的电压为220V。
【判断题】
有插销孔接头的设备,插销孔的导体应隐蔽在绝缘板平面内。
【判断题】
脉冲激光焊时,输入到工件上的能量是连续的。
【判断题】
气瓶在使用过程中必须根据国家《气瓶安全监察规程》要求进行定期技术检验
【判断题】
焊接电缆的柔软性要好,容易弯曲,以便于操作及减轻劳动强度。
【判断题】
登高焊割作业的脚手板,单人道宽度不得小于0,6m。
【判断题】
焊接带有气压的锅炉储气筒及带压附件,会造成火灾爆炸事故。
【判断题】
结构钢的焊接性,随着含碳量的提高而变得较差。
【判断题】
检修动火时,动火时间一次绝不能超过一天。
【判断题】
理弧焊时,交流电源多用于大电流埋弧和采用直流时磁偏吹严重的场合。
【判断题】
等离子弧的引弧频率一般为5000Hz。
【判断题】
压缩空气的作用不包括对碳棒电极起冷却作用。
【判断题】
发生火灾,应迅速拔打火警电话"119"报警。
【判断题】
对电焊过程中产生的强弧光如不采取防护措施,作业人员易发生白内障等眼病。
【判断题】
触电的现场急救是整个触电急救工作的关键。
【判断题】
在特别潮湿的场所焊接,人必须站在潮湿的木板或橡胶绝缘片上。
【判断题】
对处于窄小空间位置的焊缝,只要轻巧的刨枪能伸进去的地方,就可以进行切割作业。
【判断题】
激光探头给出的电信号与所检测到的激光能量成正比。
【判断题】
一次性工亡补助金标准为上一年度全国城镇居民人均可支配收入的20倍。
【判断题】
凡进行登高作业和进入登高作业区域,焊工必须戴好安全帽。
推荐试题
【单选题】
Q3: What does the speaker say about negative feelings?___
A. People should turn every negative feeling around .
B. Negative feelings can sometimes have positive effects .
C. Negative feelings often cause people to make mistakes .
D. People should never show negative feelings in public places .
【单选题】
Q4: What is the main idea of the passage?___
A. People should learn to manage their emotions .
B. People should be patient with their negative feelings .
C. People should learn to analyze causes of unhappiness .
D. People should identify as many positive feelings as possible .
【单选题】
Q1: What are the man and woman talking about?___
A. Whether nature is magical and kind .
B. Whether nature is powerful and full of risks .
C. Whether Christopher was well prepared for the trip .
D. Whether Christopher's trip to Alaska was worthwhile .
【单选题】
Q2: What can we learn about Christopher?___
A. He made a film about his trip to Alaska .
B. He wrote a story about his trip to Alaska .
C. He died while having an adventure in Alaska .
D. He learned how powerful and risky Alaska was .
【单选题】
Q3: What does the woman think about Christopher taking the trip to Alaska?___
A. He was too foolish .
B. He was really romantic .
C. He had a very kind heart .
D. He had a spirit for trying things .
【单选题】
Q4: Which of the following is NOT mentioned as something that would have saved Christopher’s life?___
A. A gun to hunt .
B. The map of the area .
C. Emergency food supplies .
D.
E. mergency communication equipment .
【单选题】
Q1: What speed can an avalanche reach within five seconds of taking off?___
A. At 8 miles an hour .
B. At 18 miles an hour .
C. At 80 miles an hour .
D. At 88 miles an hour .
【单选题】
Q2: According to the passage, under what circumstances may an avalanche occur?___
A. There are too many layers of snow on the .
B. There is a layer of snow covering an entire area .
C. The top layer of snow slides off the layer below it .
D. The layer of snow below the surface becomes unstable .
【单选题】
Q3: What are skiers advised to do to avoid being caught in an avalanche?___
A. Ski only in the official ski areas .
B. Look for solid snow to walk on .
C. Look out for each other while skiing .
D. Learn to control themselves in an avalanche .
【单选题】
Q4: Why does the ski patrol use explosives?___
A. To dig holes in the snow .
B. To close the area for skiing .
C. To make an avalanche move on purpose .
D. To' check how different layers are holding up .
【单选题】
Q1:What is conversation mainly about?___
A. The woman's happy college life the man's doubt .
B. The woman's spending habits and the man's concerns .
C. The man's reminding the woman of the exam this Thursday .
D. The man's support for the woman over the past 15 years .
【单选题】
Q2:What did the woman do last night?___
A. She bought a new leather coat .
B. She studied very hard for an exam .
C. She treated all her friends to dinner .
D. She went to a concert with her friends .
【单选题】
Q3:Where did the woman get the money?___
A. She just received her student loan .
B. She saved some money for herself .
C. She borrowed the money from her friends .
D. She asked her mom to send her the money .
【单选题】
Q4:What is the man?___
A. A teacher of biology .
B. An undergraduate student .
C. A freshman in biology class .
D. A graduate teaching assistant .
【单选题】
Q1: What is this passage mainly about?___
A. How businesses can compete with each other .
B. How small businesses operate during holidays .
C. How small businesses manage holiday workers .
D. How can earn more money during holidays .
【单选题】
Q2: According to Rubin, what can small companies do to thank holiday workers?___
A. Have talks with their families .
B. Give them good extra benefits .
C. Offer them expensive holiday tokens .
D. Show appreciation to them face to face .
【单选题】
Q3: What can small business owners do to help holiday workers get into the holiday spirit?___
A. Entertain them with big meals .
B. Let them enjoy some holiday games .
C. Give them handmade thank-you cards .
D. Send their families some holiday gift cards .
【单选题】
Q4: Who are supposed to benefit most from this passage?___
A. Workers who have to work during holidays .
B. Employees who intend to earn extra money .
C. Big companies that usually close on holidays .
D. Small businesses that try to be more competitive .
【单选题】
In the first two paragraphs of the passage the writer tries to tell us that___
A. he had lived in Washington D.C. for twenty years
B. he was very imaginative when he was a child
C. he had fond memories of his old neighborhood
D. )he had come from a very poor neighborhood
【单选题】
The writer ,as a child ,was very fond of playing in the basement because ___
A. it was bright and alive
B. it contained a movie house and a space station
C. it was ideal for playing hide-and-seek
D. it was surrounded by trees and flowers
【单选题】
How did the writer feel when he visited his old neighborhood in Washington D.C. ?___
A. Greatly surprised .
B. Very regretful .
C. Quite excited .
D. Very sad .
【单选题】
On his visit to his hometown ,the writer found the old apartment building___
A. see medunfit to live in
B. had been repaired
C. could hardly be recognized
D. looked dirty and smelt horrible
【单选题】
" Youcan never go home again "inthe last sentence of this passage means that___
A. one should never revisit his hometown after many years of absence
B. one will never find his hometown the same as it was in his childhood memory
C. avisit to one's hometown will bring back one's fond memories of home
D. avisit to one's hometown will bring back many sad memorie
【单选题】
We learn from the passage that Tracy died___
A. on December 8,1992
B. of brain damage
C. 24 hours after he fell off the roof of a car
D. in a car crash
【单选题】
Tracy's parents decided to donate Tracy's organs because___
A. Tracy told them to do so just before he died
B. they wanted to save others the pain of seeing a dear one die
C. David's life could continue in a meaningful way
D. they knew David was suffering from a hopeless liver disease
【单选题】
The meeting between the writer's family and Tracy's parents was arranged because___
A. the writer and her husband wished to express their thanks to Tracy's parents
B. the local organ bank wanted to see how both families felt about the donation
C. Tracy's parents wanted to see someone whose life had been saved by the donation
D. the two families were linked by the most bittersweet ties imaginable
【单选题】
The writer and her husband learned how Tracy died___
A. from his parents
B. from the organ bank
C. from the hospital
D. from the doctor who performed the operation
【单选题】
The meeting between the two families helped to ease the Marshes'suffering because___
A. they saw that David looked very much like their son
B. they saw that David had regained health with Tracy's liver
C. they now had someone to share their memories of Tracy
D. they now knew for sure they had done the right thing
【单选题】
The writer's first marriage was unsuccessful because___
A. her husband often woke her up at midnight
B. her husband kept criticizing her
C. she was so unattractive
D. she had a self-esteem problem
【单选题】
When the writer asked for a divorce ,her husband___
A. told her that she would never find one who loved her as he did
B. delayed two years before giving her a reply
C. accused her of having an affair
D. said that she was unattractive and not worth loving
【单选题】
When the writer first met Clint ,she felt that___
A. she should have listened to her friend and met Clint earlier
B. Clint was a nice ,dazzling young man
C. Clint could not be really interested in her
D. she would find true love in Clint
【单选题】
The writer was particularly touched by Clint because___
A. he loved her children and asked for their approval of the marriage
B. he said that he could not imagine a life without her and the children
C. he believed that at 2 and 4 ,the two children were the "menof the house "
D. hekept her company and talked with her until the next morning
【单选题】
The writer's marriage to Clint is important to her mainly because___
A. it gave her and her sons a second chance to live a happy life
B. every day Clint would tell the writer that he loved her
C. it helped her to regain her self respect
D. it made her children happy ,which is all she cared about in life
【单选题】
What was Goodall's childhood dream ?___
A. She dreamed of going to college .
B. She dreamed of studying animals in Africa .
C. She dreamed of becoming a scientist .
D. She dreamed of traveling all around the world .
【单选题】
What did Goodall's mother think of her dream ?___
A. As a girl she should not go to the African jungle .
B. Her dream would remain a dream unless she got the right training .
C. As a girl she should stay away from violent animals .
D. She could make her dream come true if she was determined .
【单选题】
Goodall's most important discovery was that___
A. some animals use tools
B. like humans animals have emotions
C. chimpanzees could attack each other violently
D. termites are chimpanzees'favorite food
【单选题】
Goodall's success is chiefly due to her___
A. exceptional talents
B. scientific training
C. determination and patience
D. enthusiasm and good luck
【单选题】
What is Goodall doing now ?___
A. Studying animal behavior at Cambridge University .
B. Raising funds for the preservation of wildlife .
C. Observing chimpanzees in African jungles .
D. Working hard supervising postgraduate students.
【单选题】
___是我们理解当前所处历史方位的关键词。
A. 新时期
B. 新时代
C. 重要战略机遇期
D. 关键期
【单选题】
中国特色社会主义进入新时代,意味着科学社会主义在21世纪的中国焕发出强大生机活力,在世界上高高举起了___伟大旗帜。
A. 小康社会
B. 社会主义现代化强国
C. 和谐社会
D. 中国特色社会主义
