问题 问答题 简答题

简述缓慢冻结时浓缩的危害性。

答案

参考答案:

(1)溶质沉淀-有沙粒感;

(2)浓度太大-蛋白质变性;

(3)PH下降,等电点-蛋白质沉淀;

(4)干扰平衡-使得胶体不稳定;

(5)气体过饱和——逸出;

(6)组织脱水——失去复原性。

完形填空
完形填空。
     Everyone must go to bed early and get up early, or we won't be healthier and clever.
     Is this true? Perhaps it is. The body must have   1   sleep. Children of your age need   2   sleep every day. If
you don't go to bed early, you   3   enough sleep, then you can't think properly and can't do your work properly.
You will not be clever.
     Some people go to bed late and get up late. This is not good   4   them. We must sleep at nine when it is dark. The dark help us   5  .When the daytime comes, we must get up. This is time for exercises. If you lack exercises, it becomes   6  . Exercises help a strong body.
     Exercises help the blood (血液) flow around   7   the body. This is very important. Blood takes food   8   all
parts of our body, the brain (大脑) needs blood. We think   9   our brain. If we keep our body   10   and take
exercises, we can think better.
( )1. A. enough   
( )2. A. ten hours
( )3. A. will have
( )4. A. to      
( )5. A. to sleep
( )6. A. to weak 
( )7. A. outside 
( )8. A. to     
( )9. A. of    
( )10. A. health 
B. many     
B. ten hours'
B. can have  
B. for     
B. sleeping   
B. strong     
B. out of    
B. with     
B. about    
B. healthing 
C. some    
C. ten hour's
C. won't have
C. with    
C. slept   
C. weak    
C. into    
C. out of  
C. with    
C. healthy   

D. very       
D. ten-hours' 
D. have         
D. of         
D. to sleeping  
D. healthy      
D. inside       
D. from         
D. in           
D. doing      

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