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问题 单项选择题

标准正态分布曲线下中间90%面积所对应的横轴尺度μ的范围是

A．-1.282到+1.282
B．-∞到+1.282
C．-1.645到+1.645
D．-∞到+1.645
E．以上都不对

答案

参考答案：C

完形填空
完形填空。

      Mr. Roy likes to travel    1   in his spare time. He likes to sit beside the window and look the scenery
 through the window when he is on a train. One day he went to travel himself. He   2   a seat near windows
as soon as he got on the train. He found that all of window seats were taken. He went on another railway
carriage. He found out one. There was a young man sitting in the seat   3   this one. Mr. Roy was happy
that the young man hadn't   4   the seat by the window. He went to the seat quickly. When he   5   it, Mr.
Roy saw that there was a piece of paper   6   some words on the seat. It said,"This seat is broken. You can't
take it, Please find another seat. Thank you.""A broken seat on a train? Is that   7   ?" Mr. Roy said   8   sadly,
but he walked on and found   9   empty seat. It isn't beside a window. He had to sit in. When the train would
  10  , a very beautiful girl got on the train. The young man quickly took the paper off the seat beside his as
soon as he saw her, and let the girl sit in during the whole trip.

( )1. A. by bus    
( )2. A. found out
( )3. A. on      
( )4. A. sat      
( )5. A. reached   
( )6. A. and       
( )7. A. good      
( )8. A. loudly  
( )9. A. other     
( )10. A. reach  

B. by train    
B. found        
B. beside    
B. taken        
B. arrived       
B. with       
B. comfortable
B. happily      
B. others      
B. stop        		C. by ship       
C. looked for      
C. in            
C. put          
C. saw             
C. for           
C. dangerous     
C. to the young man
C. another         
C. begin         		D. by plane   
D. looked       
D. under       
D. seen         
D. got           
D. of         
D. possible    
D. to himself
D. the other     
D. got        
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单项选择题

一端管板固定在壳体与管箱之间，另一端管板可以在壳体内自由移动的是（）换热器。

A、固定管板式

B、U形管式

C、浮头式

D、板翘式
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