如图所示,理想变压器的原副线圈匝数比n1:n2=1:10,副线圈与阻值R=20Ω

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问题:

如图所示,理想变压器的原副线圈匝数比n1:n2=1:10,副线圈与阻值R=20Ω的电阻相连.原线圈两端所加的电压u=20sin20πt(V),则(  )

A.副线圈输出交流电的频率为10Hz

B.交流电压表的示数为20V

C.电阻R上消耗的电功率为2kW

D.原线圈中电流的最大值为100A

考点:变压器的结构和原理
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对于美国人口总体来说平均的期望寿命是73.9岁,但是在夏威夷出生的小孩子将平均77岁,而那些在路易斯安那出生的人将平均活到71.7岁。如果一对从路易斯安那来的新婚夫妇在夏威夷开始他们的家庭生活,那么,他们的孩子预期将比他们留在路易斯安那的情况下活得更长。 以下哪一论述,如果是正确的,将最显著地加强短文中得出的结论( )

A.有利于长寿的环境因素在夏威夷有很多,而在路易斯安那州比较少

B.所有迁移到夏威夷去的路易斯安那人中,有25%的人活过了77岁

C.过去10年中,路易斯安那人的平均寿命预期比夏威夷人上升的速度更快

D.研究表明,那些永久地迁移到路易斯安那州的夏威夷人的平均寿命预期同那些留在夏威夷的夏威夷人大致相同

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有献不死之药于荆王①者,谒者②操以入。中射之士③问曰:“可乎?”曰:“可。”夺而食之。王怒,使人杀中射之士。中射之士使人说王曰:“臣问谒者,谒者曰:‘可食。’臣故食之。臣无罪,而罪在谒者也。且客献不死之药,臣食之,而王杀臣,是死药也。王杀无罪之臣,而人之欺王。”王乃不杀。   (《战国策》)

注释:①荆王:楚王,疑为顷襄王。②谒者:禀报的人。③中射之士:即中射士,王宫的卫士。

小题1:解释下列划线的字。(2分)

(1)可乎(       )    (2)夺而食之(    )

(3)臣无罪(        ) (4)而人之欺王(    )

小题2:翻译句子。(2分)

且客献不死之药,臣食之,而王杀臣,是死药也。

小题3:根据文中内容回答。(2分)

中射之士认为自己不该杀,讲了哪几条理由?(用自己的话来说)

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下列句子标点符号的使用,正确的一句是(    )

A.你是参加电子计算机培训班呢?还是参加理论物理学习班呢?

B.澳大利亚海关当局正在对代表团成员的历史记录进行反复核对,以核实在参加过悉尼奥运会和2002年盐湖城冬奥会以及即将参加雅典奥运会的运动员中,是否有人涉嫌走私兴奋剂。

C.金老师对他的学生说:“我们在学习上要不断进步,否则就要后退。古语不是说‘学如逆水行舟,不进则退嘛’。”

D.本来约好下午两点钟碰面,可我等了二、三个小时,他才来。

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D

People often say that the Englishman’s home is his castle. They mean that the home is very important and personal to him. Most people in Britain live in houses rather than flats, and many people own their homes. This means that they can make them individual(个体的); they can paint them, and change them in any way they like. Most houses have a garden, even if it is a very small one, and the garden is usually loved. The house and the garden are the private(私人的) space of the individual.

People usually like to mark their space. Are you sitting now in your home or on a train Have you marked the space around yourself as yours If you are on the train you may put your coat or small bag on the seat beside you. If you share a flat you may have one corner or chair which is your own.

Once I was travelling on a train to London. I was in a section for four people and there was a table between us. The man on the opposite side to me had his briefcase on the table. There was no space on my side of the table at all. I was angry. Maybe he thought that he owned the whole table. I had read a book about nonverbal communication, so I took various papers out of my bag and put them on his briefcase! When I did this he stiffened and his eyes nearly popped(瞪出)out of his head. I had invaded(侵犯)his space! A few minutes later I took my papers off his case in order to read them. He immediately moved his case to his side of the table. Of course, it is possible that he just wanted to be helpful to me!

If you are visiting another country you may feel that you don’t have any private space. Hotel rooms look much the same in every country in the world. All day long, you share public spaces with other people. You see the local people in their private spaces and you feel lonely and "outside". Local people can create their private spaces by talking about things you don’t know about. And you even feel that they like you to be outside them so that they will enjoy being inside even more! This is one of the difficulties of being a traveller! But if you understand it then it helps you. Haven’t you enjoyed being part of a group and" owning" a bit of space

Which of the following is TRUE according to the passage()

A.British people dislike marking their space.

B.You always feel at home in another country.

C.Most British people prefer living in houses to flats.

D.You can’t mark your private space in a foreign country.

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酚类化合物的命名是以酚为()体。在酚的名称前面写出()基的名称及位置。

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