如图为远距离输电示意图,升压变压器与降压变压器的匝数比分别为1:100和100:

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问题:

如图为远距离输电示意图,升压变压器与降压变压器的匝数比分别为1:100和100:1,发电

站输出电压为u=250sin100πt(V),下列说法正确的是(  )

A.用户得到的交变电压频率为50Hz

B.用户得到的交流电压有效值为250V

C.用电高峰期升压变压器的输出电压不变

D.输送过程中电能的损耗主要来自变压器原、副线圈的发热

考点:远距离输电的相关计算
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在计算机中用KB、MB、GB、TB等单位来表示存储容量,其中1GB=1024MB。

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现需要能输出36V直流电压的直流电源,若采用单相桥式整流,则整流变压器副边电压应为()V。

A.32.4

B.40

C.64.8

D.80

题型:多选题

读等高线地形图,回答

(1)图中字母所表示的地形部位分别是:G______,E______.

(2)图中AD线和BD线所在地,坡度比较陡的是______.

(3)图中甲村庄在乙村庄的______方向

(4)如果要修一座水库,大坝应修在______处(用字母表示).

题型:多选题

重力是决定色彩的不对称平衡的一个重要要素,而重力受多种因素的影响,例如花纹面料服装上的强调色只有大些,才能引起重视,这说明()影响重力。

A、对比强弱

B、位置

C、背景繁简

D、内在兴趣

题型:多选题

阅读理解。

     For many years, I stuck to the idea that my suffering was because of my size. I believed that when the

weight disappeared, it would take old wounds, hurts, and rejections with it.

     Many weight-conscious people also mistakenly believe that changing our bodies will fix everything.

Perhaps our worst mistake is to believe that being thin equals being loved, being special, and being cherished

(珍爱). We fantasize (幻想) about what it will be like when we reach the long-awaited goal. We work very

hard to realize this dream. Then, at last, we find ourselves there. 

     But we often gain back what we have lost. Even so, we continue to believe that next time it will be

different. Next time, we will keep it off. Next time, being thin will finally realize its promise of everlasting

happiness, self-worth, and of course, love.

     It took me a long while to realize that there was something more for me to learn about beauty. Beauty

standards are different with culture. In Samoa, a woman is not considered attractive unless she weights

more than 200 pounds. More importantly, if it's happiness that we want, why not put our energy there rather

than on the size of our body? Why not look inside? Many of us work hard to change our body, but in vain.

We have to find a way to live comfortably inside our body and make friends with and cherish ourselves.

When we change our attitudes toward ourselves, the whole world changes.

1. The passage tries to make the readers realize the importance of _____. [ ]

A. attitudes toward ourselves

B. culture difference

C. body size

D. different beauty standards

2. The word "everything" in Paragraph Two probably refers to _____. [ ]

A. all the efforts

B. all the problems

C. the whole world

D. the total truth

3. What can be inferred about the author? [ ]

A. The author was once troubled by her/ his weight.

B. The author succeeded in losing weight.

C. The author probably got wounded in wars or accidents

D. The author is a Samoan.

4. The best title for the passage probably is _____. [ ]

A. Lose all your wounds with your weight

B. Beauty: standard varies with culture

C. Change your attitude rather than your shape

D. It will be different next time

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