设数列{an}的前n项和为Sn,若2an=Sn+1,则数列{an}的通项公式是_

题型:填空题

问题:

设数列{an}的前n项和为Sn,若2an=Sn+1,则数列{an}的通项公式是______.

考点:数列的概念及简单表示法
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最应警惕的优降糖不良反应为()。

A.低血糖反应

B.过敏反应

C.胃肠道反应

D.白细胞减少

E.乳酸性酸中毒

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机械加工时,从工件表面切去的一层金属称为加工余量。

题型:填空题
完形填空。

     Most of us can remember the days when we didn't use e-mail as an everyday vehicle for communication.
Slowly but surely, it crept (慢慢移动) into   1   . E-mail is a   2   tool for college students at any level. It's
available 24 hours a day,7 days a week and   3   at holidays. Most universities assign students an account
entrance,   4   there is usually not even an option (选择) involved.
     You can do everything from consulting on homework and projects,   5   classmates, family and friends,
and getting daily new services to  6   you informed of world  7   . But, what are the  8  ? E-mail can be e-jail.
You might   9   hours writing and replying to e-mails  10   you should be busy with the books for an upcoming
exam. 
  11   ,you might be signed up for so many daily services,   12   horoscopes (占星术), new services, or
personals, that your mailbox is so   13   "junk mail",that finding the  14  e-mails through your box might take
hours.
      If you're a student,  15   is precious. Create and organize your e-mail folders into important school-related
mail, correspondence (通信)with friends and family, and a folder for jokes, horoscopes and other new services. 
  16   put the mail into the proper folders first, and when you've finished, head for the important school-related
folder first. Respond to the most important e-mails first and,   17   you have time, you can get to the others. 
       18  your friends from forwarding those tiresome jokes, tiresome quizzes, and chain mails. The minute you 
  19   you've got one, delete it   20   so you won't be tempted to read it.

( )1. A. the lives          
( )2. A. valuable           
( )3. A. even               
( )4. A. but                
( )5. A. keeping touch with 
( )6. A.keeping             
( )7. A. accidents          
( )8. A. advantages  takes  
( )9. A. spend              
( )10. A. for               
( )11. A. Otherwise       
( )12. A. such as          
( )13. A. full up with      
( )14. A. important         
( )15. A.money              
( )16. A.Sometimes         
( )17. A. if                
( )18. A. Encourage         
( )19. A.examine            
( )20. A.later            

B. life              
B. changeable        
B. still             
B. so                
B. getting touched to
B. keep              
B. incidents         
B. mistakes          
B. cost              
B. because           
B. Or                
B. such like         
B. full              
B. necessary         
B. mark              
B. Always            
B. although          
B. Watch             
B. check up          
B. immediately       
C. our lives         
C. favorable         
C. ever              
C. because           
C. losing touch with 
C. leaving           
C. events            
C. wrongs            
C. take              
C. since             
C. But               
C. for example       
C. filled up with    
C. practical         
C. grade             
C. Almost          
C. since           
C. Discourage        
C. find              
C. after           
D. us life               
D. usable                
D. yet                   
D. except that           
D. keeping in touch with 
D. leave                 
D. things                
D. disadvantages         
D. pay                   
D. when                  
D. However               
D. so as                 
D. fill with             
D. possible              
D. time                  
D. Usually               
D. because               
D. Refuse                
D. realize               
D. soon                  
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检验轻链病(Lightchaindisease)最可靠的方法为()

A.血清蛋白电泳

B.尿蛋白电泳

C.脑髓液蛋白电泳

D.血清免疫球蛋白定量

E.血红蛋白电泳

题型:填空题

Excel2000中在( )选项中设置文本跨列居中

A.文本方向

B.文本控制

C.水平对齐方式

D.垂直对齐方式

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