如图所示要改变通电导体AB的运动方向,下面方法正确的是 [ ] A.升高电源电压

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问题:

如图所示要改变通电导体AB的运动方向,下面方法正确的是

[ ]

A.升高电源电压

B.增大通过电动机线圈的电流强度

C.把电源正、负极对调

D.把电源正、负极对调的同时,将电动机磁铁的两极也对调

考点:磁场对通电导线的作用
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“华盛顿,异人也。起事勇于胜、广,割据雄于曹、刘;既已提三尺剑开疆万里,乃不僭位号,不传子孙,而创为推举之法,几于天下为公,夫三代之遗意!”其中的“不僭位号,不传子孙,而创为推举之法"是指美国宪法确立的

A.联邦制

B.共和制

C.总统制

D.三权分立体制

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严重的腺垂体功能减退症易发生低血糖主要是缺乏()。

A.PRL及LH

B.PRL及TSH

C.PRL及ACTH

D.GH及TSH

E.GH及ACTH

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GSM主要接口协议分为三层,其中第三层包括三个基本子层()、()和()。

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Children start out as natural scientists, eager to look into the world around them. Helping them enjoy science can be easy ;there’s no need for a lot of scientific terms or expensive lab equipment. You only have to share your children’s curiosity. Firstly,listen to their questions. I once visited a classroom of seven-year-olds to talk about science as a job. The children asked me" textbook questions" about schooling, salary and whether I liked my job. When I finished answering, we sat facing one another in silence. Finally I said, "Now that we’ve finished with your lists, do you have questions of your own about science"
After a long pause ,a boy raised his hand," Have you ever seen a grasshopper(蚱蜢) eat When I try eating leaves like that, I get a stomachache. Why"
This began a set of questions that lasted nearly two hours.
Secondly, give them time to think. Studies over the past 30 years have shown that, after asking a question, adults typically wait only one second or less tor an answer, no time for a child to think. When adults increase their" wait time" to three seconds or more, children give more logical, complete and creative answers.
Thirdly, watch your language. Once you have a child involved in a science discussion, don’t jump in with" That’s right" or" Very good". These words work well when it comes to encouraging good behavior. But in talking about science, quick praise can signal that discussion is over. Instead, keep things going by saying" That’s interesting" or" I’d never thought of it that way- before", or coming up with more questions or ideas.
Never push a child to" Think". It doesn’t make sense, children are always thinking, without your telling them to. What’s more, this can turn a conversation into a performance. The child will try to find the answer you want, in as few words as possible, so that he will be a smaller target for your disagreement.
Lastly, show;don’t tell. Real-life impressions of nature are far more impressive than any lesson children can learn from a book or a television program. Let children look at their fingertips through a magnifying glass, and they’ll understand why you want them to wash before dinner. Rather than saying that water evaporates, set a pot of water to boil and let them watch the water level drop.

According to the passage, children can answer questions in a more logical, complete and creative way if adults______.

A. ask them to answer quickly
B. wait for one or two seconds after a question
C. tell them to answer the next day
D. wait at least for three seconds after a question

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关于ILS进近不正确的是:()

A、执行CAT1标准时以气压为基准,应使用进近页面的MDA/H

B、执行CAT2/3时应输入DA/H

C、在使用QFE的机场运行时,飞行计划中所有限制高度单位均应为转换后的英尺

D、在使用QFE的机场运行时,备用高度表拨正值应始终为QNH值

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