下列不是变频器作用的是()。 A.调速 B.能量再生 C.保护负载设备 D.节

题型:单项选择题

问题:

下列不是变频器作用的是()。

A.调速

B.能量再生

C.保护负载设备

D.节

考点:集输工考试集输工数字化(中级)集输工数字化(中级)题库
题型:单项选择题

阅读理解。

     Miss Evans taught physics in a London school. Last month she was explaining to her class about

sound, and she decided to test them to see how successful she had been in her work. She said to them,

Now, I have a sister in Washington. If I was calling her on the telephone, and at the same time you were

20 meters away and listened to me from the other side of the street, who could hear what I said earlier,

my sister or you? And why?

    The cleverest boy at once answered, "Your sister, Miss Evans, because electricity (电) travels faster

than sound waves(波)." That's very good, Miss Evans answered, but then one of the girls put up her hand, and Miss Evans said, Yes, Betty?

     "I don't think so. Betty said, Your sister would hear you earlier because when it's eleven o'clock here,

it's only six o'clock in Washington."

1. Miss Evans was teaching her class ______.     

A. about sound                      

B. to hear some strange sound

C. about electricity                    

D. how to say time

2. She wanted to make her students know______.      

A. whether she could hear her sister in Washington

B. whether her students could hear her from 20 meters away

C. which was faster, London or Washington

D. electricity travels faster than sound waves

3. The cleverest boy thought that______.

A. sound waves travel faster than electricity

B. they would hear her sister in Washington first

C. Miss Evans's question wasn't right

D. Miss Evans's sister would hear her earlier

4. Miss Evans______.       

A. thought Betty's answer was much better

B. thought the cleverest boy's answer wasn't so good

C. was satisfied with what the girl had said

D. was satisfied with(对...感到满意) what the cleverest boy had said

5. Betty thought the cleverest boy was wrong, because______.

A. clocks in Washington showed a different time from those in London

B. electricity was slower than sound waves

C. they were only 20 meters away from the telephone

D. electricity travels as fast as sound waves

题型:单项选择题

在下列酶中,能够促使脂肪酶水解的是[ ]

A.淀粉酶

B.蛋白酶

C.脂肪酶

D.麦芽糖酶

题型:单项选择题

对声门型喉癌描述正确的是().

A.在喉癌中最常见

B.多发生于声带的前1/3~1/2处

C.病理类型多为高分化鳞癌

D.早期声门癌淋巴结转移少见

E.声门癌单纯放疗的疗效与手术相当

题型:单项选择题

下列说法中关于工程竣工结算的说法错误的是()。

A.对于工程竣工结算报告金额在2000万元~5000万元的,审查时间为从接到竣工结算报告和完整的竣工结算资料之日起20天

B.工程竣工结算分为单位工程竣工结算、单项工程竣工结算和建设项目竣工结算

C.单位工程竣工结算由承包人编制,发包人审查

D.建设项目竣工总结算在最后一个单项工程竣工结算审查确认后15天内汇总,送发包人后20天内审查完成

E.单项工程竣工结算或建设项目竣工总结算由总(承)包人编制,发包人直接审查

题型:单项选择题

所有项目过程中输出的相关文件(纸件、电子件)的命名不包含()

A、运营商名

B、产品

C、工程期号

D、华为公司名

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