过电压、过电流是怎样产生的?它对变压器有何影响?

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问题:

过电压、过电流是怎样产生的?它对变压器有何影响?

考点:矿井机电维修工矿井机电维修工题库
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下列不能反映下图给我们的启示的是

A.国 * * 障公民受教育权利的实现

B.我们青少年要珍惜受教育权利,努力学习

C.教育公平能促进社会稳定发展

D.教育公平了,社会就公平了。

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隧道防水混凝土抗渗标号以每组试件中有( )个未发现渗水现象时的最大水压力表示。

A.3
B.4
C.5
D.6

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Part 4


Questions 26-45


·Read the following text and decide which answer bestfits each space.
·For questions 26-45, mark one letter A, B, C or D on the Answer Sheet.

Newspapers


Who won the World Cup 1994 football game What happened at the United Nations How did the critics like the new play When an event takes place, newspapers are on the streets (26) the details. (27) anything happens in the world, reporters are on the spot to (28) the news.
Newspapers have one basic (29) to get the news as quickly as possible from its source, from those who make it to those who want to (30) it. Radio, telegraph, television, and (31) inventions brought competition for newspapers. So did the development of magazines and other means of communication. (32) this competition merely spurred the newspapers on. They quickly made (33) of the newer and faster means of communication to improve the speed and (34) the efficiency of their own operations. Today more newspapers are printed and read than ever before.
Competition also led-newspapers to branch out into many other fields. Besides keeping readers (35) of the latest news, today’s newspapers (36) readers about politics and other important and serious matters. Newspapers influence readers’ economic choices (37) advertising. Most newspapers depend on advertising for their very (38) Newspapers are sold at a price that (39) to cover even a small fraction of the cost of production. The main (40) of income for most newspapers is commercial advertising. The (41) in selling advertising depends on a newspaper’s value to advertisers. This is measured (42) circulation. How many people read the newspaper Circulation depends (43) on the work of the circulation department and on the services or entertainment (44) in a newspaper’s pages. But for the most part, circulation depends on a newspaper’s value to readers as a source of information (45) the community, city, country, state, nation, and world—and even outer space.

A.Wherever

B.Whoever

C.Whatever

D.Whichever

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()应当至少对滑行道、机坪、升降带、跑道端安全地区、飞行区围界、巡场路巡视检查一次。

A.每6小时

B.每12小时

C.每日

D.每两日

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大气污染物急慢性危害均有,应制订

A.一次最高浓度
B.日平均最高浓度
C.一次最高容许浓度
D.日平均最高容许浓度
E.C+D

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