下列离子方程式正确的是． A．碳酸钙与醋酸溶液反应：CaCO3+2CH3COOH

发布时间：2017-04-26 13:11 │ 来源：www.tikuol.com

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下列离子方程式正确的是．

A．碳酸钙与醋酸溶液反应：CaCO₃+2CH₃COOH=Ca²⁺+2CH₃COO^-+H₂O+CO₂↑

B．碳酸氢镁溶液中加入足量的烧碱溶液：Mg²⁺+ 2HCO₃^-+ 2OH^-= MgCO₃↓+ CO₃^2-+ 2H₂O

C．Fe(NO₃)₃的酸性溶液中通入足量硫化氢：2Fe³⁺＋H₂S=2Fe²⁺＋S↓＋2H⁺

D．H₂¹⁸O中投入Na₂O₂：2H₂¹⁸O＋2Na₂O₂=4Na⁺＋4OH^－＋¹⁸O₂↑

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完形填空。
Tom and Fred were talking about the year 2050. 　　"What will 1 be like in the year 2050?" asked Tom. 　　"I don't know," said Fred. "What do you think?" 　　"Well, no one knows. But it is 2 to guess," said Tom. "In the year 2050 everybody will 3 a pocket (袖珍)computer. The computer will give people the 4 to all their problems. We shall all have telephones in our pockets, 5 . 　　And we'll be able to talk to our friends all over the world. Perhaps we'll be able to 6 them at the same time. Machines will do 7 of the work, and people will have more 8 . Perhaps they will work Only two or three days a week. They will be able to fly to the moon by spaceship and spend their holidays there." 　　"I'm very 9 to hear that. I hope to fly to the moon. And I hope I'll be able to live 10 ," said Fred. "Won't that be interesting? Just like a fish."
( )1. A. our home ( )2. A. pleased ( )3. A. carry ( )4. A. news ( )5. A. either ( )6. A. call ( )7. A. most ( )8. A. work ( )9. A. sorry ( )10. A. in the sea	B. the traffic B. no use B. bring B. ways B. again B. see B. many B. duty B. glad B. on land	C. a factory C. interesting C. give C. things C. too C. look C. lot C. holidays C. sure C. on the mountain	D. the world D. unusual D. send D. answers D. also D. listen D. every D. times D. afraid D. under the ground

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下列各句中标点符号使用正确的一项是（）

A．中学生是如何支配压岁钱呢？我们应该如何正确使用压岁钱呢？你是否想过用它来做一些有意义的事？（比如捐给希望工程等）。对上述问题，我们作了一些调查。

B．徐悲鸿笔下的马，正如有的评论家所说的那样，“形神兼备，充满生机。”现已成为该美术馆的镇馆之宝。

C．2003年，教育部制订了中学语文“新课标”——《普通中学语文课程标准》——该课标是构建符合素质教育要求的新的语文基础课程的依据。

D．她一手提着竹篮，内中一个破碗，空的；一手拄着一支比她更长的竹竿，下端开了裂：她分明已经纯乎是一个乞丐了。

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目前，我国银行业金融机构所办理的信用证业务程序，大致有哪几个环节（）

A.申请开证

B.开立信用证

C.审核信用证

D.议付索汇

E.付款赎单

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一、二级耐火等级单层、多层丙、丁、戊类厂房之间的防火间距不应小于（）米。

A、8

B、10

C、12

D、14

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简述育苗的要求及壮苗的标准。

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