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(2011?张掖)鸡蛋壳的主要成分是碳酸钙.某兴趣小组为了测定鸡蛋壳中CaCO3的含量,现取15g鸡蛋壳,捣碎,放在烧杯中,然后向其中加入80g某浓度的稀盐酸,使之充分反应(鸡蛋壳中除CaCO3外的其他成分都不溶于水,且不与稀盐酸反应),测得烧杯中的反应剩余物的质量(m)与反应时间(t)的关系如图所示(忽略水蒸气的挥发),其中当反应进行到B点时,所用盐酸刚好完全反应.试计算(计算结果保留1位小数):

(1)产生CO2的质量为_________g;
(2)该鸡蛋壳中CaCO3的质量分数.
(3)反应后滤去不溶物所得溶液中溶质的质量分数.

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空气的成分中,约占总体积78%的气体是(   )
A.氮气B.氧气C.二氧化碳D.稀有气体

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下列物质中,属于氧化物的是(  )
A.H2OB.NaClC.NaOHD.C2H5OH

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最清洁的燃料是(  )
A.煤B.汽油C.氢气D.一氧化碳

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下列物质与水混合,能形成溶液的是(  )
A.沙子B.蔗糖C.氯化银D.植物油

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NaOH溶液的pH(  )
A.等于0B.小于7C.等于7D.大于7

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科目: 来源: 题型:阅读理解


It’s not easy to be an astronaut’s son.Everybody expects you to be special or perfect.I
often wonder how my father ever had a son like me.I mean he’s so special and so good at
everything he does.Even in middle school he was class president and captain of the football
team.
Well,to be honest,I often dream about being some kind of hero or doing something
special—like saving a child from a burning building or discovering a new star.I was daydreaming at school one morning when my teacher said there would be a Father’s Day writing competition for the whole sch001.“I hope we have a winner right here in my class.”
When I got home,I started to think about what to write.My father is an astronaut.N0,I
wouldn’t start like that.That was the way others saw him.How did I see my father? Hmm.
I saw him sitting with me in the dark when I had a terrible dream.I remembered how he
hugged me for hours when my dog Spotty was killed by a car.Yes,these were the things I
was going to write.To me,he wasn’t just a world—famous astronaut.He was my dad.
My parents and l went to school Thursday night.There were so many people in the big
hall! My dad looked at me,and I shrugged(耸肩).
The third prize was announced and it was not me.1 was relieved(释然)and disappointed at the same time.The second prize was announced.It was me.
1 went up to the stage and read what I had written,“My father’s son”.When I finished,the people stood up and cheered.I saw my father blowing his nose.Tears were running down my mother's face.Dad cleared his throat and put his hand on my shoulder.“Son,this
is the proudest moment of my life.’’
It was the proudest moment of my life,too.Maybe I’ll never be a great hero or win a
Nobel Prize,but it was enough just to be my father’s son.
根据材料内容选择最佳答案,并将其标号填入题前括号内。
【小题1】The writer felt it       to be the son of a famous person.
A.1uckyB.naturalC.hardD.pleasant
【小题2】In order to_       the writer would like to save a child from a burning building.
A.become astronautB.become a great hero
C.be made school team captainD.be made class president
【小题3】What did the boy probably write in his composition?
A.A lot of special things he had done.
B.The story of his father as an astronaut.
C.The unforgettable time he spent with his father.
D.The experiences his father had in middle school.
【小题4】The writer felt proud when he          
A.got a prize in a writing competitionB.won a Nobel Prize
C.saved a child from a burning buildingD.discovered a new star
【小题5】What is the best title for the passage?
A.My daydreamB.My father’s son
C.My famous fatherD.My happy family

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