三相发动机绕组一般不采用()连接。A、三角形 B、星形 C、Y形 D、以上三种都行

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问题:

三相发动机绕组一般不采用()连接。

A、三角形

B、星形

C、Y形

D、以上三种都行

考点:矿井维修电工矿井维修电工(初级)矿井维修电工(初级)题库
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Thomas Alva Edison (爱迪生)was awarded more patents(专利) on inventions than any other American. When he died in 1931, Americans wondered how they could best show their respect for him. One suggestion was that the nation observe a minute or two of total blackout(关闭,中断). All electric power(电源) would be shut off in homes, streets, and factories. Perhaps his suggested plan made Americans realize fully what Edison and his inventions mean to them. Electric power was too important to the country. Shutting it off for even a short time would have led to complete confusion(混乱). A blackout was out of the question.

On the day of Edison’s funeral (葬礼),many people silently dimmed(使暗淡) their lights. In this way they honoured the man who had done more than anyone else to the great force of electrity

小题1: This says that Thomas Edison __________.

A.was the only important American inventor

B.received the first American patent

C.received more patents than any other American

D.was the first American inventor小题2: People decided to honor Edison when ________.

A.he made the first electric light

B.electric power was 100 years

C.the country realized electricity’s importance

D.he died in 1931小题3: The suggested plan was to _________.

A.turn off the lights in factories

B.observe a few minutes of total silence

C.dim all electric lights

D.shut off all electricity for a short time小题4: The plan was never carried out because________.

A.not everyone wanted to honor Edison

B.it was too difficult

C.electric power was too important to the country

D.it honored only one of Edison’s inventions

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按压模连接用压模的形状是否对称可分为()和整体压接两类。

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一个人的道德宗教修养在于:()

A、征服自我的修养

B、克服利己的修养

C、培养最高道德的修养

D、接近神的程度

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图片格式是指图片在计算机上的存储格式;网上一般常用的存储格式不正确的是()。

A.JPEG/JPG

B.GIF

C.PNG

D.PSD

题型:单项选择题

操作者必须遵守“定人定机”、“持证操作”制,严格按()要求,正确使用与精心维护设备。

A、整齐;

B、清洁;

C、润滑;

D、安全。

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