制备氰氨基化钙的化学方程式为CaCO3+2HCN=CaCN2+CO↑+H2↑+C

题型:选择题

问题:

制备氰氨基化钙的化学方程式为CaCO3+2HCN=CaCN2+CO↑+H2↑+CO2↑,在反应中(  )

A.氢元素被氧化,碳元素被还原

B.HCN是氧化剂不是还原剂

C.CaCN2是氧化产物,H2是还原产物

D.CO为氧化产物,H2为还原产物

考点:氧化还原反应的本质和特征氧化还原反应的定义
题型:选择题

Robby was 11 when his mother dropped him off for his first piano lesson. I prefer students begin at an earlier age. Robby insisted that it had always been his mother’s dream to hear him play the piano, so I took him in as a student.

Robby tried and tried while I listened and encouraged him and gave him more instructions (指导). But he just did not have any inborn ability.

I only saw his mother from a distance. She always waved and smiled but never came in. Then one day Robby stopped coming to our lessons. I thought about calling him but I guessed he had decided to try something else.

I was also glad that he stopped coming for the sake of my career. However, several weeks before the recital (演奏会) of my students, Robby came,telling me that he never stopped practicing and begged me to allow him to take part. I agreed but I made him perform last in the program, so I could always save his poor performance through my “curtain closer”.

I was surprised when he announced that he had chosen one piece of Mozart’s. Never had I heard a piece of Mozart’s played so well by someone at his age. When he finished, everyone was cheering.

I ran up and put my arms around Robby in joy. “I’ve never heard you play like that, Robby!  How’d you do it?”

“Well, Miss Hondorf. Do you remember I told you my mom was sick? Actually she died this morning. She was born deaf so tonight was the first time she could hear me play. I wanted to make it special. I knew I could.”  That night, Robby was the teacher and I was the student. He taught me so many important things about life.

小题1:Why did Robby stop coming to the piano lessons suddenly?

A.He lost heart and believed that he would never make it.

B.His mother was too sick to send him to the piano lessons.

C.He thought his teacher disliked him.

D.His mother died and he didn’t need to play any longer.小题2: Which statement is NOT true according to the passage?

A.The writer thought playing the piano shouldn’t start too late.

B.The writer thought that Robby had given up the piano lesson.

C.The writer taught Robby carefully although he hadn’t a gift for music.

D.No one else could play the piece of Mozart’s well.小题3:From the underlined sentence we can infer that  _______.

A.the writer looked down upon Robby and disliked him

B.the writer thought Robby a bad advertisement for his teaching

C.with Robby present, the other children couldn’t play well

D.the writer couldn’t teach so many students at a time小题4: What did the writer learn from Robby?

A.The meaning of true love.

B.The meaning of giving up necessarily.

C.The meaning of being kind to teachers.

D.The meaning of believing in teachers.

题型:选择题

核内中子数为N的R2+,质量数为A,则n g它的同价态氧化物中所含电子物质的量为(  )

A.

n
A+16
(A+N-10)mol

B.

N
A
(A-N+6)mol

C.(A-N+2)mol

D.

n
A+16(A-N+8)mol

题型:选择题

下列哪项为急性感染性多神经根炎中的急性感染脱髓鞘性多神经根炎(AIDP)型的最重要的电生改变()。

A.运动神经传导速度减慢

B.感觉神经传导速度减慢

C.运动单位波幅降低

D.纤颤电位、束颤电位

E.远端潜伏期正常

题型:选择题

“新小说”派作家罗伯-格里耶的哪部作品()被改编成电影,名为《谎言者》。

A.《橡皮》

B.《变化》

C.《纽约革命计划》

D.《咖啡壶》

题型:选择题

典型的柔性制造系统(FMS)的三个基本部分组成有:加工制造系统、计算机控制系统和()

A.物料储运系统

B.信息采集系统

C.信息处理系统

D.监控检测系统

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