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问题 填空题

I．根据下列化学方程式回答问题：

SiO2+2C+2Cl2

△
.
SiCl4+2CO

（1）反应中电子转移的数目是______．

（2）在该反应中，还原剂是______．

II．请写出下列反应的化学方程式．

（1）在制作印刷电路板的过程中常利用铜与氯化铁溶液反应______．

（2）利用铝与二氧化锰反应来制取高熔点金属锰______．

（3）过氧化钠可用作呼吸面具中的供氧剂______．

答案

I．SiO2+2C+2Cl2

△
.
SiCl4+2CO中，C元素的化合价升高，Cl元素的化合价降低，

（1）C元素的化合价由0升高为+2价，该反应中转移电子为2×（2-0）=4e-，故答案为：4e-；

（2）因C元素的化合价升高，则C为还原剂，故答案为：C；

II．（1）铜与氯化铁溶液反应生成氯化亚铁和氯化铜，该反应为2FeCl3+Cu=2FeCl2+CuCl2，

故答案为：2FeCl3+Cu=2FeCl2+CuCl2；

（2）铝与二氧化锰反应生成氧化铝和Mn，该反应为4Al+3MnO2

高温
.
2Al2O3+3Mn，

故答案为：4Al+3MnO2

高温
.
2Al2O3+3Mn；

（3）过氧化钠与二氧化碳反应生成碳酸钠和氧气，该反应为2Na2O2+2CO2=2Na2CO3+O2↑，

故答案为：2Na2O2+2CO2=2Na2CO3+O2↑．

完形填空
完形填空。
     I went back to China as soon as school was over at the end of June from Canada. It's    1    to go back
to China this summer because of the A (H1N1) flu. Everybody seemed to be    2   . The easiest thing for us
to do was to wear masks (口罩) on the plane, as my mom suggested. However, it was not    3   to wear a
mask for ten hours. I decided to put the masks into my bag    4   wearing them.
     Everything seemed OK    5   the flight. I saw only five people wear masks all the time. When we arrived
in Beijing, some    6    came into the plane and took our temperature. Fortunately,    7   had a fever. Therefore,
I was able to get home on time.
     However, everything went wrong after I got home. I became sick, with a sore throat and a fever because
I had not    8    my mom's words. Luckily, I just had a common    9  . While I was sick in bed, I thought that
if I had listened to my mom at first, I   10   would have never caught the cold. It's always wise to listen to
your mom's suggestions.
( )1. A. difficult   
( )2. A. happy      
( )3. A. necessary   
( )4. A. thanks for   
( )5. A. before      
( )6. A. policemen  
( )7. A. somebody    
( )8. A. followed   
( )9. A. stomachache 
( )10. A. differently  		B. impossible   
B. nervous      
B. healthy     
B. instead of  
B. by        
B. doctors          
B. anybody    
B. heard     
B. toothache   
B. particularly 		C. easy       
C. excited    
C. unfair      
C. because of  
C. after      
C. engineers      
C. nobody       
C. known       
C. cold       
C. usually   		D. important     
D. sad           
D. comfortable   
D. except for    
D. during                             
D. reporters     
D. everybody     
D. understood    
D. headache    
D. probably    
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单项选择题

良好的全冠轴面形态有利于保护（）

A.基牙的牙周膜

B.基牙的牙龈

C.基牙的牙槽骨

D.基牙不破折

E.全冠不破折
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