问题 问答题 简答题

什么是消化?样品消化的一般原则是什么?

答案

参考答案:

在水质监测工作中,大多数污水和沉积物等样品都含有有机物,分析前一般均需进行予处理,以破坏有机物、使样品转变成适合操作的溶液,样品的前处理过程叫做消化,样品一般用酸进行消化。样品消化的一般原则有四点

(1)消化过程中不得使待测组分受损失;

(2)不得引进干扰物质;

(3)要安全快速,不给后续操作步骤带来困难;

(4)制得的溶液要适用于选定的测定方法。

问答题
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完形填空。
     I can still remember when I met my best friend. She had just moved into the neighborhood and her
grandmother brought her down to    1   me. I hid behind my mother and she hid behind her
grandmother,   2    to look at each other. Soon we lost the   3   and started playing with each other.
In the 7th grade, I first lost touch with her. She was    4   family problems and I deserted her to be with
the   5   people. None of my new friends liked her as much as I did because they knew she had   6  .
However, every summer we   7    always sit at each other's house, watch soap operas, and talk about
all the boys we liked.
It was last year when I noticed the problem. I guess I was   8   devoted in high school to   9    she
needed someone there. Anyway, she made a new best friend and so did I. Then I didn't know why,
   10   she started cutting herself!
     She then was diagnosed(诊断)with clinical depression. At first, I was very     11  , but we still stayed
in    12    I wanted to be there with her since her new best friend basically   13    her and people were
calling her    14  .
     Yesterday she came to me and said, "I never knew what a best friend was    15    you, the only person,
would stop me cutting. I   16     your help so much, and you didn't even know you were    17    me."
We both cried. And I guess a kind of    18    from my life so far is never to give up on your friends. Even
if they aren't as cool as others, or people think they are crazy, they need    19    there. If you desert them,
you will only be   20    yourself.
( )1. A. follow  
( )2. A. scared    
( )3. A. temper    
( )4. A. taking up  
( )5. A. happier  
( )6. A. problems  
( )7. A. should  
( )8. A. much      
( )9. A. admit    
( )10. A. but     
( )11. A. calm     
( )12. A. place  
( )13. A. confused  
( )14. A. crazy  
( )15. A. unless  
( )16. A. expect  
( )17. A. urging  
( )18. A. honour  
( )19. A. someone  
( )20. A. innocent  
B. meet        
B. annoyed        
B. interest      
B. getting through
B. cooler        
B. shortcomings  
B. could          
B. too            
B. accept        
B. for            
B. considerate    
B. touch          
B. bothered      
B. stubborn      
B. as            
B. influence      
B. blaming        
B. favour        
B. something      
B. successful    
C. join       
C. worried      
C. confidence    
C. going through  
C. stronger      
C. partners      
C. would        
C. only          
C. consider      
C. or           
C. upset        
C. control      
C. reminded      
C. clumsy        
C. until        
C. appreciate    
C. helping      
C. pleasure      
C. anyone        
C. guilty        
D. support        
D. delighted      
D. shyness        
D. making up    
D. cleverer      
D. disabilities  
D. might          
D. just          
D. realize        
D. so            
D. helpful        
D. mood          
D. deserted      
D. stupid        
D. that          
D. demand        
D. hurting        
D. lesson        
D. everything    
D. reliable