如图所示,三盏灯丝电阻分别为R1=10欧,R2=15欧,R3=30欧,电压表V1

题型:填空题

问题:

如图所示,三盏灯丝电阻分别为R1=10欧,R2=15欧,R3=30欧,电压表V1示数为U1,V2示数为U2,则U1:U2=______;此时电路的总电阻为______欧.

考点:电阻的串联串联电路的电压规律电压的测量,电压表的使用串、并联电路的辨别
题型:填空题

Many people go to school for education.They learn languages,history,geography, physics , chemistry and math.Others go to school to learn a skill__1___they can make a living. School education is very important and useful,but no one can learn _2____ from school. A teacher,no matter how much he knows,can’t teach his students everything they want to know. The teacher’s.job is to show his students how to read and  3 to think.So much more is to be learned out of school students themselves.
It is always more important to know how to study by oneself than to memorize some  5  or formulas(公式).It is actually quite  6  to learn a certain fact in history or a formula in mathematics.But it is very difficult to use a formula in working out a math problem. Great scientists such as Einstein,Newton and Galileo,didn’t learn many things from school, but they were all  and invented many things for mankind.
The  8 for their success is that they knew how to study.They read books that were not  9 at school . They worked hard all their lives 10 not a single minute . They would ask many questions as they read and they did thousands of experiments.
小题1:
A.even ifB.so thatC.becauseD.once
小题2:
A.everythingB.somethingC.anythingD.nothing
小题3:
A.whatB.whichC.howD.why
小题4:
A.byB.withC.onD.in
小题5:
A.meaningsB.booksC.historyD.facts
小题6:
A.necessaryB.easyC.differentD.common
小题7:
A.cleverB.popularC.successfulD.patient
小题8:
A.experimentB.reasonC.resultD.way
小题9:
A.keptB.shownC.expressedD.taught
小题10:
A.spendingB.wastingC.costingD.taking
题型:填空题

随机接入采用的前导码有哪三类?()

A、PreambleGroupA;

B、PreambleGroupB;

C、PreambleGroupC;

D、专用Preamble。

题型:填空题

R1和R2两只电阻串联,已知R1=5欧,且两端的电压为2伏,若R2=10欧,则R1和R2两端的总电压为_________,R1和R2的总功率为_________.

题型:填空题

男,45岁,有肺结核史,近1个月来咳嗽、低热,痰中带血,胸片示:左肺上叶不张。

下列哪项因素对预后影响最大()

A.肿物巨大

B.中央型肺癌

C.癌肿的组织学类型及分化程度

D.术前已有肺不张

E.出现骨关节综合征

题型:填空题

质量管理八项原则可以指导组织意在通过关注顾客的需求预期而达到( )的目的。

A.确保顾客满足

B.改进其总体业绩

C.评定质量管理体系运行状

D.提高领导作用

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