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问题 选择题

2.1g平均相对分子质量为7.2的CO和H2组成的混合气体与足量的O2充分反应后，立即通入足量的Na2O2固体中，充分反应，固体的质量增加（　　）

A．2.1g

B．7.2g

C．9.3g

D．以上答案均不正确

答案

CO与H2在氧气中完全燃烧，生成CO2和H2O，生成的CO2和H2O再与Na2O2反应．2CO+O2 

 点燃 
.
 
2CO2，一氧化碳与二氧化碳物质的量相等，Na2O2与CO2反应2CO2+2Na2O2=2Na2CO3+O2，质量增重△m=2Na2CO3-2Na2O2=2CO，可知反应后固体质量增加量为CO的质量；

2H2+O2

 点燃 
.
 
2H2O，生成的水与氢气物质的量相等，Na2O2与H2O反应2H2O+2Na2O2=4NaOH+O2，质量增重△m=2H2O-O2=2H2，可知，反应后固体增加的质量为氢气质量．

所以2.1gCO和H2的混合气体在足量氧气中充分燃烧后，将产物立即通入盛有足量Na2O2的反应管，固体质量增重为2.1gCO和H2的混合气体的质量．

故选：A．

完形填空

One day a woman got into her car and started driving home after work. Just at that time, she saw a __26__ car behind her. The driver was a __27__. When she turned left, the yellow car turned left. When she turned __28__, the yellow car turned right, too. When she stopped at the traffic lights, the yellow car stopped __29__ her..

The woman was __30__, so she drove quickly to __31__. When she arrived, she was very __32__ to see that the yellow car stooped behind her again. But she felt __33__ because she saw a policeman standing outside the police station. She jumped out of her car at once and __34__ to the policeman. She asked the policeman to arrest（逮捕）the man in the yellow car, then the police man walked to the man.

The man didn’t run away. He just __35__ and said to the woman, “I want to give this purse back to you. I think you dropped it on the street.”

小题1:A. red                          B. yellow                     C. black

小题2:A. man                         B. woman                    C. policeman

小题3:A. left                       B. back                       C. right

小题4: A. opposite                   B. before                     C. behind

小题5: A. anxious                  B. scared                     C. pleased

小题6: A. the police station            B. her office                C. her home

小题7: A. interested                  B. excited                    C. surprised

小题8: A. sad                       B. safe                        C. dangerous

小题9:A. ran                       B. run                         C. runs

小题10:A. cried                     B. laughed                   C. smiled
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单项选择题

有如下程序：　　Private Sub Commandl_Click( )　　　　Dim i As Integer　　　　For i=1 To 2　　　　　　DS　　　　Next i　　　End Sub　　　Sub DS( )　　　　Dim x As Integer，m As String　　　　Static y，n　　　　X=X + 1　　　　y=y + 1　　　　m=m &"*”：n=n&"#"　　　　Print x，y，m，n　　End Sub　　程序运行后，输出的结果是()。

A． * p表示的是指针变量p的地址

B． p表示的是变量a的地址，而不是变量a的值

C． * p表示的是指针变量p的值

D． * p只能用来说明p是一个指针变量
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