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问题 单项选择题

血小板的主要功能是

A．具有吞噬病原微生物的作用

B．具有缓冲酸碱变化的作用

C．限制速发性变态反应

D．促进生理止血与凝血

E．运输血液中的O2和CO2

答案

参考答案：D

完形填空
完形填空。
      Jack buys     1     beef. The butcher (屠夫) tells him the recipe and gives him some relish.
"But I can't remember your words." Jack says. "Will you write them    2    for me?" The butcher
does     3     .    4      the meat in his hand and the note in his pocket, Jack goes home     5     .
A dog runs     6     him on the way. Suddenly it comes     7      him, takes the meat away      8    
 him and runs off. Jack stands there and doesn't know      9    . After a while he laughs and says,
"Never mind. You don't know how      10     it. The recipe is still in my pocket."
( )1. A. a cup of 
(     )2. A. in       
( )3. A. so       
(     )4. A. Have    
( )5. A. happily  
(     )6. A.in        
( )7. A. on       
( )8. A. of       
( )9. A. what to do
( )10. A. cooking  		B. a teaspoon of
B. at          
B. that        
B. With        
B. happy       
B. out         
B. after       
B. from        
B. why         
B. to cook      		C. a box of       
C. down           
C. it             
C. In             
C. sad              
C. of            
C. at             
C. to               
C. what does he do
C. cooked          		D. a piece of   
D. on              
D. such         
D. On              
D. sadly         
D. after           
D. out               
D. with       
D. where he is                 
D. eat     
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填空题
已知a＞b≥c＞0，且2a2+
1
ab
+
1
a(a-b)
-4ac+4c2=4，则a+b+c=______．
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