拉瓦西把少量汞(俗称水银)放在密闭的容器里连续加热12天,结果发现,有一部分银白

题型:问答题

问题:

拉瓦西把少量汞(俗称水银)放在密闭的容器里连续加热12天,结果发现,有一部分银白色的液态汞变为红色粉末,同时,容器里的空气的体积大约减少了五分之一.剩余的气体不能供给呼吸,也不支持燃烧.通过这一实验你对空气的成分有何认识?

考点:空气的成分
题型:问答题

如图所示,是用某种玻璃制成的横截面为圆形的圆柱体光学器件,它的折射率为,横截面半径为R。现用一束细光线垂直圆柱体的轴线以i=60°的入射角射入圆柱体,不考虑光线在圆柱体内的反射,真空中光速为c。

(1)作出光线穿过圆柱体并射出的光路图。

(2)求出该光线从圆柱体中射出时,出射光线偏离原方向多大的角度?

(3)光线在圆柱体中的传播时间。

题型:问答题
As a young boy my family was very poor. I would often help do something for the neighbors to  36  a little pocket money.
One day I  37  on the door of an elderly woman and asked  38  she needed me to clean the yard. She asked why I was not in  39  and I showed her my worn  40 , which no longer kept me warm. She  41  me to work in the yard. When I finished, she looked at me and said, “I suppose you want to be  42  now.” She then  43  a jar filled with dollar bills and said, “I’m glad you’ve done a  44  job today but that is not something you should be doing again. I want you to  45  new clothes and get back to school. I also want you to come back to  46  me with your report card and I will  47  you when I see you have worked hard and have some good  48 . Now reach out your little hands and take out as much  49  as you can.”
I put my hands in the jar and  50  so much money that it was  51  for me to buy what I badly needed. Later, I returned several times to see the woman and she did just as she  52 . She looked at my report card and gave me a handful of dollars and some delicious food every time I  53  her that I had an “A”.
I was twelve years old when I moved from that neighborhood. I will never forget the huge  54 this wonderful lady made over my life with her  55 . This is something I hope to do myself in this lifetime over and over again.
小题1:
A.saveB.giveC.earnD.change
小题2:
A.turnedB.knockedC.workedD.looked
小题3:
A.howB.whenC.why D.if
小题4:
A.schoolB.timeC.troubleD.bed
小题5:
A.bagB.carpetC.coatD.sofa
小题6:
A.allowedB.forcedC.helpedD.stopped
小题7:
A.punishedB.testedC.praisedD.paid
小题8:
A.set up B.took outC.talked aboutD.put away
小题9:
A.boringB.newC.fineD.terrible
小题10:
A.keepB.buyC.removeD.make
小题11:
A.visitB.forgiveC.welcomeD.serve
小题12:
A.recognizeB.rewardC.understandD.protect
小题13:
A.goalsB.storiesC.marksD.ideas
小题14:
A.roomB.moneyC.foodD.time
小题15:
A.grabbedB.lostC.borrowedD.charged
小题16:
A.rareB.enoughC.simpleD.special
小题17:
A.promisedB.discoveredC.knewD.admitted
小题18:
A.askedB.requiredC.showedD.wrote
小题19:
A.decisionB.progressC.mistakeD.difference
小题20:
A.courageB.kindnessC.honestyD.happiness
题型:问答题

以下对金融机构现金清分中心发现人民币假币后的操作表述正确的是()

A.立即报告现场负责人并换人复核

B.填写《假币代保管登记簿》

C.假币实物加盖“假币”印章并用专用袋封存妥善保管

D.假币实物不加盖“假币”印章并用专用袋封存单独妥善保管

题型:问答题

由氧化镁制取氯化镁的过程中,为什么要加碳?

题型:问答题

考试实施程序规定语文、英语科目开考前(),所有工作人员佩戴规定工作胸牌到考点考务室集中,接受考点主任指示和工作安排。

A、30分钟

B、25分钟

C、40分钟

D、20分钟

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