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问题 选择题

用基因工程技术构建抗除草剂的转基因烟草过程中，下列操作错误的是[ ]

A．用限制性核酸内切酶切割烟草花叶病毒的核酸

B．用DNA连接酶连接经切割的抗除草剂基因和载体

C．将重组DNA分子导入烟草原生质体

D．用含除草剂的培养基筛选转基因烟草细胞

答案

答案：A

单项选择题 A1型题

霉菌是没有较大子实体的一部分真菌而且菌丝体（）

A.比较不发达

B.发达

C.比较发达

D.不发达

E.以上都不对
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     The town I live in is about to put cameras at all traffic lights to catch people who run red lights. It   1   
me of how many people I've seen who take the yellow light as a   2   to go faster. I also can't understand
why people don't move when the traffic light has turned green. Above all, there are those   3   situations in
which someone doesn't even   4   that the light turns red, and just keeps going. That is why so many   5  
 happen! All these situations make me   6   the purpose of traffic lights. 
       7  , it's even more frightening to imagine letting people make their own decisions at   8   crossroads.
Do the biggest cars get to go first? Who decides who goes next? So I guess I do like the idea of a system
to   9   traffic. And I'll do my best to  10  the traffic rules: to go, to be cautious, and to stop when I'm  11  
to.
     It occurs to me that my  12  have done much the same for me  13  teaching me how to live. They have
given me many  14  lights: to get along well with others, to listen and talk to them, to help others, and to  15  
with joy and purpose. They have also given me some red lights  16  my life goes astray (误入歧途): not to
be greedy, to keep my temper, and to control my desires. And there  17  have been some yellow caution lights:
to watch how much I drink, to keep control of my behavior, and to  18  school regularly and work hard.
     If I obey these rules, my life will be as  19  as it can be. Just as I'm wise to pay attention to the traffic lights
when I'm walking across the street, I'm wise to pay attention to the " 20  signals" given to me by my parents.

( )1. A. suggests    
( )2. A. sight       
( )3. A. instant     
( )4. A. notice      
( )5. A. events      
( )6. A. think of    
( )7. A. Besides     
( )8. A. noisy       
( )9. A. control     
( )10. A. learn      
( )11. A. supposed   
( )12. A. teachers   
( )13. A. in charge of 
( )14. A. safe       
( )15. A. live       
( )16. A. unless     
( )17. A. still      
( )18. A. start      
( )19. A. good       
( )20. A. traffic     		B. informs     
B. signal      
B. exciting    
B. sense       
B. problems    
B. wonder about   
B. Anyway      
B. narrow      
B. direct      
B. obey        
B. used        
B. friends     
B. in face of  
B. green       
B. share       
B. when        
B. even        
B. attend      
B. colorful    
B. light        		C. reminds    
C. message    
C. dangerous  
C. remember   
C. situations 
C. care for   
C. Instead    
C. crowded    
C. improve    
C. protect    
C. devoted    
C. leaders    
C. in terms of
C. beneficial 
C. work       
C. before     
C. only       
C. leave      
C. meaningful     
C. life        		D. warns          
D. switch         
D. cautious       
D. feel           
D. accidents      
D. worry about              
D. However        
D. key            
D. serve          
D. carry          
D. delighted      
D. parents        
D. in danger of   
D. helpful        
D. communicate    
D. till           
D. also           
D. miss           
D. healthy        
D. confidence     
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