【填空题】
15.接触器是用来接通或___主电路的一种控制电器。___
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【填空题】
16.继电器是在输入_____作用下而动作的自动控制电器。___
【填空题】
17.熔断器主要由___和熔断管两部分组成。___
【填空题】
18.客车空调三机是指空调机组、____和发电机组。___
【填空题】
19.轴温报警器是一种车载监测___温度变化,超温报警的装置。___
【填空题】
20.轴报器的中修周期与客车____周期相同。___
【填空题】
21.TKZW-1T型轴报器跟踪报警温度是____。___
【填空题】
22.三相感应电支机常用的起动方式有___起动和降压起动等两种。___
【填空题】
23.25G型客车电气设备按电压等级分为____V、220V和48V三类。___
【填空题】
24.具有安装客车发电机和蓄电池的固定设备,但暂时未安装的客车叫_____。___
【填空题】
25.客车电动水泵由直流电动机的循环___组成。___
【填空题】
26.凡实行定期检修并需分解的蓄电池,应首先进行一次部分容量的放电,叫____。___
【填空题】
27.利用晶体管电路把直流电转变为交流电,这种对应于整流的逆向过程称为_____。___
【填空题】
28.万有表使用完毕后,应将转换开关置于___档。___
【填空题】
29.一般万用表主要由表头、测量线路和___组成。___
【填空题】
30.低压电器按照它所控制的对象不同,可分为低压配电电器及___电器两种。___
【填空题】
31.通常规定兆欧表的额定转速为____r/min。___
【填空题】
32.将电气设备与零线相连叫___。___
【填空题】
33.把数字信号转换___的装置称为D/A转换器。___
【填空题】
34.电工常用的绝缘材料按其化学性质的不同,可分为___绝缘材料、有机绝缘材料和混合绝缘材料三种。___
【填空题】
35.激磁线端反接会造成KP-2A型控制箱发电机___。___
【填空题】
36.空调机组的主要噪声来自_____和风机。___
【填空题】
37.J5型发电机及恒压装置的整定电压是___V。___
【填空题】
38.25型空调客车车下配线包括输送三相交流电的主线、___及车下各负载支线等。___
【填空题】
39.最高工作温度保险丝的额定电流是指___。___
【填空题】
40.25型客车电压为____三相四线制。___
【填空题】
41.客车上使用的逆变器,其三极管的连接方式为___。___
【填空题】
42.电流互感器是配合电流表,继电保护线圈来反映___的一种特殊变压器.___
【填空题】
43.通常所说的表头灵敏度是指使表针自零点___时的电流值。___
【填空题】
44.电流所通过的路径称___。___
【填空题】
45.电路是由电源、负载、开关和___四个基本部分组成。___
【填空题】
46.电磁式交流继电器主要由____、触头部分和反力部分组成。___
【填空题】
47.在可控整流电路中,触发电路必须和____同步。___
【填空题】
48.直流电源一般由电源变压器、____、滤波器和稳压电路组成。___
【填空题】
49.在可控整流电路中,触发电路必须和____同步。___
【填空题】
50.车辆空调制冷系统中,单位时间内所摄取的热量称为___。___
【填空题】
51.25型空调客车的供电装置采用____形式。___
【填空题】
52.电感线圈在电路中具有通直流___的作用。___
【填空题】
53.交流接触器具有远距离操作功能、_____和欠压保护功能,但不具备过载保护功能。___
【填空题】
54.空调装置电气部件与壳的绝缘,在相对湿度小于60%时电阻应大于_____,若低于此值,可采用断开有关线路分段测量方法,找到漏电部位后更换或加强绝缘性能下降的元件。___
【填空题】
55.目前绝大部分空调装置的进出风温差一般在Δt=_____。___
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The Industrial Revolution was aThe Industrial Revolution was accomplished in Britain by the middle of the century.
A. A. 17th
B. B. 18th
C. C. 19th
D. D. 20th
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Britain faced strong challenges in its global imperial dominance by the beginning of the century.
A. A. 17th
B. B. 18th
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The British government is characterized by a division of powers between three of the following branches with the exception of the .
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The importance of the British monarchy can be seen in its effect on .
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British Cabinet works on the principle of .
A. A. collective responsibility
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The main duty of the British Privy Council is to .
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is the first African-American winner of the Nobel Prize for Literature.
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Of the following writers, is Not a Nobel Prize winner.
A. A. Alice Walker
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Of the following writers, is NOT included in the group of naturalists.
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Of the following, is NOT characteristic of Mark Twain’s works.
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Of the following, is considered Herman Melville’s masterpiece.
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is regarded as “the father of American literature”.
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The National Day of the United States falls on .
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Of the following, is NOT among the three major radio and TV networks in America.
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is sold especially to the upper or upper-middle class and it has a reputation for its serious attitude and great bulk.
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Of the following universities, has NOT cultivated any American President yet.
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To get a bachelor’s degree, all undergraduate students are required to do the following except .
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Of the following, is NOT the responsibility of the board of trustees in U. S. institutions.
A. A. choosing the president
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D. D. decide which student to enroll
【单选题】
Of the following, are NOT among the categories of American higher education.
A. A. universities and colleges
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C. C. technical institutions
D. D. community colleges
【单选题】
Higher education in the United States began with the founding of
A. A. Yale University
B. B. Harvard University
C. C. Princeton University
D. D. New York University
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Of the following subjects, are NOT offered to elementary school students.
A. A. mathematics and languages
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Formal education in the United States consists of , secondary and higher education.
A. A. kindergarten
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At present, U. S. exports account for of the world’s total.
A. A. 10%
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C. C. 20%
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is not one of the three giants in American automobile industry.
A. A. Ford
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The following statements are all true except .
A. A. Agribusinesses reflect the big, corporate nature of many farm enterprises.
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C. C. Agribusinesses range from one-family corporations to multinational firms.
D. D. Agribusinesses include a variety of farm businesses and structures.
【单选题】
About of American crops are for export.
A. A. half
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President Johnson tried to build a “Great Society” by introducing various programs like the following except .
A. A. Medicare
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The following inventions took place during the “second indThe following inventions took place during the “second industrial revolution” except .
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The first National Bank of the United States was established with the urge of .
A. A. George Washington
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Chartered companies were NOT granted the by the British King or Queen.
A. A. political authority
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The modern American economy progressed from to , and eventually, to .
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B. B. farming economy, handcraft economy, industrial economy
C. C. colonial economy, farming economy, industrial economy
D. D. handcraft economy, farming economy, industrial economy
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America produces a major portion of the world’s products in the following fields except .
A. A. machinery
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The President is directly voted into office by .
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The Supreme Court is composed of justices.
A. A. six
B. B. seven
C. C. eight
D. D. nine
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The terms for a Senator and Representative are and years respectively.
A. A. two, four
B. B. two, three
C. C. two, six
D. D. six, two