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【单选题】
绝缘材料的耐热等级为E级时,其极限工作温度为()℃。 ___
A. 90
B. 10^5
C. 120
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答案
C
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绝缘手套属于()安全用具。 ___
A. 辅助
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C. 基本
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可用于操作高压跌落式熔断器、单极隔离开关及装设临时接地线等。 ___
A. 绝缘手套
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雷电流产生的()电压和跨步电压可直接使人触电死亡。 ___
A. 接触
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利用()来降低加在定子三相绕组上的电压的启动叫自耦降压启动。 ___
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利用交流接触器作欠压保护的原理是当电压不足时,线圈产生的()不足,触头分断。 ___
A. 磁力
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笼形异步电动机采用电阻降压启动时,启动次数()。 ___
A. 不允许超过3次/小时
B. 不宜太少
C. 不宜过于频繁
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笼形异步电动机常用的降压启动有()启动、自耦变压器降压启动、星-三角降压启动。 ___
A. 串电阻降压
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笼形异步电动机降压启动能减少启动电流,但由于电机的转矩与电压的平方成(),因此降压启动时转矩减少较多。 ___
A. 正比
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漏电保护断路器在设备正常工作时,电路电流的相量和(),开关保持闭合状态。 ___
A. 为负
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螺口灯头的螺纹应与()相接。 ___
A. 零线
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螺丝刀的规格是以柄部外面的杆身长度和()表示。 ___
A. 厚度
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螺旋式熔断器的电源进线应接在()。 ___
A. 下端
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落地插座应具有牢固可靠的()。 ___
A. 标志牌
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每一照明(包括风扇)支路总容量一般不大于()kW。 ___
A. 3
B. 2
C. 4
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某四极电动机的转速为1440r/min,则这台电动机的转差率为()%。 ___
A. 4
B. 2
C. 6
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脑细胞对缺氧最敏感,一般缺氧超过()min就会造成不可逆转的损害导致脑死亡。 ___
A. 8
B. 5
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频敏变阻器其构造与三相电抗相拟,即由三个铁芯柱和()绕组组成。 ___
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钳形电流表测量电流时,可以在()电路的情况下进行。 ___
A. 短接
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钳形电流表使用时应先用较大量程,然后在视被测电流的大小变换量程。切换量程时应()。 ___
A. 先退出导线,再转动量程开关
B. 直接转动量程开关
C. 一边进线一边换挡
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钳形电流表是利用()的原理制造的。 ___
A. 电压互感器
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钳形电流表由电流互感器和带()的磁电式表头组成。 ___
A. 整流装置
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墙边开关安装时距离地面的高度为()m。 ___
A. 1.3
B. 1.5
C. 2
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确定正弦量的三要素为()。 ___
A. 相位、初相位、相位差
B. 最大值、频率、初相角
C. 周期、频率、角频率
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热继电器的保护特性与电动机过载特性贴近,是为了充分发挥电机的()能力。 ___
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热继电器的整定电流为电动机额定电流的()%。 ___
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热继电器具有一定的()自动调节补偿功能。 ___
A. 时间
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人体体内电阻约为()Ω。 ___
A. 300
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C. 500
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人体同时接触带电设备或线路中的两相导体时,电流从一相通过人体流入另一相,这种触电现象称为()触电。 ___
A. 单相
B. 两相
C. 感应电
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人体直接接触带电设备或线路中的一相时,电流通过人体流入大地,这种触电现象称为()触电。 ___
A. 单相
B. 两相
C. 三相
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日光灯属于()光源。 ___
A. 气体放电
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熔断器在电动机的电路中起()保护作用。 ___
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如果触电者心跳停止,有呼吸,应立即对触电者施行()急救。 ___
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C. 俯卧压背法
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三相对称负载接成星形时,三相总电流()。 ___
A. 等于零
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三相交流电路中,A相用()颜色标记。 ___
A. 黄色
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三相笼形异步电动机的启动方式有两类,既在额定电压下的直接启动和()启动。 ___
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【单选题】
Q4: According to the passage, what will bring people good luck?___
A. Breaking a mirror on purpose .
B. Catching a falling leaf on one's birthday .
C. Finding a on the ground and picking it up .
D. Dreaming of blowing out the candles in one blow .
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Q1: How long will the woman spend on her way to and from work by high-speed train?___
A. 4 hours .
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D. 45 minutes .
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A. At 8 .
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Q3: According to the woman, in what way will the new high-speed train be a big help to her?___
A. She can either read or rest a little on the  train .
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D. She can go shopping on her way home  from work .
【单选题】
Q4: How will the new high-speed train affect the man?___
A. He can take the train to the old part of the  city .
B. He can save a lot of money when he takes  the train .
C. He can save 20 minutes to go to work with  the train .
D. He can take the train to the airport instead  of driving .
【单选题】
Q1: How much time on average do Americans spend on their way to work?___
A. About an hour .
B. More than an hour .
C. About half an hour .
D. More than one and a half hours .
【单选题】
Q2: What is the present situation about Americans’ commuting to work?___
A. More and more Americans spend over an  hour getting to work .
B. Over 10 percent of Americans spend less  than an hour getting to work .
C. Only New York people spend more than  90 minutes getting to work .
D. Over 10 percent of Americans spend more  than 90 minutes getting to work .
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Q3: Why does Steven choose to have an extreme commute?___
A. Because gas prices are not high .
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C. Because he can attend a better school .
D. Because he can have his favorite lifestyle .
【单选题】
Q4: Which of the following is the disadvantage of long commutes?___
A. Traffic jams .
B. Expensive housing .
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D. A tiring and boring trip .
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Q1: What did Katy like about Jason’s last Halloween party?___
A. She liked playing an interesting game .
B. She enjoyed seeing many of her old friends .
C. She enjoyed wearing her Halloween costume .
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【单选题】
Q2: What is the actual reason that Katy doesn’t want to attend Jason’s party?___
A. None of her friends likes Jason .
B. None of Jason's guests is young .
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【单选题】
Q3: What is special about Linda’s party?___
A. The party will last four hours .
B. Six people will attend the party .
C. They will have huge bags of candy .
D. They will play a new game called "GuessWho ".
【单选题】
Q4: What will Katy do to solve her problem?___
A. Go to Jason's party .
B. Go to Linda's party .
C. Attend both Jason's and Linda's parties .
D. Celebrate Halloween with her parents .
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Q1: What is special about this year’s Black Friday shopping?___
A. Some stores offered bigger holiday discounts .
B. Some stores provided more choices of nightlife.
C. Some stores made efforts to attract young people .
D. Some stores opened much earlier than they used  to .
【单选题】
Q2: Why did some stores open at midnight on Thanksgiving night?___
A. To attract young customers .
B. To beat other stores for sale.
C. To let people sleep late the next day .
D. To keep people stay up for the night .
【单选题】
Q3: How many Black Friday shoppers were reported to go to the shops at midnight this year?___
A. 24 percent .
B. 37 percent .
C. 9.5 percent .
D. 23.5 percent .
【单选题】
Q4: What can we learn about the 15-year-old Jenny?___
A. She and her cousins went back home at midnight .
B. She liked the traditional 4 a.m. Black Friday.
C. She preferred midnight shopping to early  morning shopping .
D. She and her cousins got up very early to buy  discounted items .
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Q1: Why did the woman decide to do a triathlon?___
A. Because she did it in college .
B. Because she wanted to be tough .
C. Because her sister did it and liked it .
D. Because her sister said it was good for her .
【单选题】
Q2: When did the man first do a triathlon?___
A. Last year .
B. In college .
C. Last week .
D. In high school .
【单选题】
Q3: How does the man feel about running?___
A. Boring.
B. Scaring .
C. Exciting .
D. Interesting .
【单选题】
Q4: Why doesn’t the woman like swimming in the triathlon?___
A. Because she fears that a big fish might eat  her .
B. Because she fears that she would get lost in  lakes .
C. Because she doesn't want to scare away  small fishes .
D. Because she doesn't like swimming with  many people .
【单选题】
Q1: What is the ratio of positive to negative emotions that can make a person happier?___
A. 1:3.
B. 3 :1.
C. 1 :10 .
D. 10 :1.
【单选题】
Q2: What is the most exciting finding about increasing positive emotions?___
A. It improves relationships .
B. It leads to greater success .
C. It helps develop creativity .
D. It contributes to good health .
【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 .
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