问题 单项选择题 A型题

2D计划系统的局限性包括()

A.只能获得治疗部位有限的靶区和重要器官的几何近似体模图

B.对非共面射野设计几乎不可能

C.剂量计算忽略了射野本身线束的三维扩散

D.剂量分布只能分层显示,没有评估工具

E.A+B+C+D

答案

参考答案:E

解析:2D计划系统有许多局限性,一方面是只能借助扫描仪描绘体表轮廓图或拍摄治疗部位的正侧位片获得患者治疗部位有限的靶区和重要器官的几何近似体模图,对非共面射野设计几乎不可能。另一方面剂量计算忽略了射野本身线束的三维扩散,最后的剂量分布只能分层显示,因没有评估工具,只能通过观察等剂量线与靶区和重要器官间的关系进行评估。

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     Jerry is the kind of man you love to hate.He is always in a(n)__1__mood and always has something
__2__to say.In his opinion, the bottom line is your choice__3__you live a life.
     One morning, he did something you are never__4__to do in the restaurant business: he left the back
door open and was__5__up at gunpoint by three armed robbers.While trying to open the__6__, with
his hand shaking from__7__, he input the wrong code.The robbers beat him and even__8__him.Luckily,
Jerry was found__9__quickly after the robbers had fled and he was rushed to the local first aid center.
After 18 hours of operation and weeks of good care, he was out of hospital with fragments (碎片) of
the bullets still in his body.
     Jerry told me what happened after he was sent to hospital.He said the doctors were  10  .They kept
telling him he was going to be fine and  11   him into the emergency room.But when he saw the  12   on
the faces of the doctors and nurses, he got really  13  .In their eyes, he 14  , "He's dying." He knew he
needed to take 15  .There was a big,burly nurse shouting questions at him.She asked if he was allergic
(过敏的) to anything, and the doctors and nurses stopped working as they waited for his reply.Jerry
  16   for a while and then he decided to live.He took a deep breath and said, "Yes.  17  !" Over their
laughter, Jerry told them to operate on him  18   he wouldn't die.
     Jerry lived, thanks to the skill of his doctors, but also because of his amazing  19  .I learnt from him
that every day we have the choice to live fully.
     Attitude,  20   , is everything.
( )1. A. exciting      
( )2. A. positive      
( )3. A. how            
( )4. A. advised        
( )5. A. pulled        
( )6. A. box            
( )7. A. nervousness    
( )8. A. knocked        
( )9. A. probably      
( )10. A. excited      
( )11. A. rolled        
( )12. A. surprise      
( )13. A. scared        
( )14. A. knew          
( )15. A. notice        
( )16. A. thought      
( )17. A. Medicine      
( )18. A. unless        
( )19. A. reply        
( )20. A. to be honest  
B. good          
B. funny        
B. where        
B. imagined      
B. put          
B. safe          
B. worry        
B. killed        
B. relatively    
B. organized    
B. carried      
B. expressions  
B. embarrassed  
B. found        
B. order        
B. wondered      
B. Operation    
B. even if      
B. attitude      
B. in that case  
C. usual        
C. new          
C. whether      
C. asked        
C. held          
C. counter      
C. unwillingness
C. knifed        
C. merely        
C. hardworking  
C. wheeled      
C. feeling      
C. disappointed  
C. meant        
C. breath        
C. judged        
C. Bullets      
C. as if        
C. opinion      
C. after all    
D. balanced              
D. different              
D. why                    
D. supposed              
D. done                  
D. door                  
D. pressure              
D. shot                  
D. reasonably            
D. great                  
D. forced                
D. puzzles                
D. annoyed                
D. read                  
D. action                
D. stopped                
D. Fragments              
D. before                
D. determination          
D. strictly speaking      
单项选择题