搜题请搜索小程序“爱下问搜题”
问题 选择题

下图为反射弧结构示意图，下列有关说法不正确的是

[ ]

A．由ABCDE组成了一个完整的反射弧

B．当①处受刺激时，该处的膜电位表现为外正内负

C．②处的结构决定了神经元之间的兴奋传递只能是单向的

D．若从①处剪断神经纤维，刺激③处，效应器仍能产生反应

答案

答案：B

单项选择题

喷管中空气流的速度为500m/s，温度为300K，密度为2kg/m3若要进一步加速气流，喷管面积应（）。

A．缩小

B．扩大

C．不变

D．不定
查看答案
完形填空
完形填空

     On the first day of my school life in the USA, I showed a great interest in my marketing class. My
teacher, Mrs. Tolman, suggested I  __1__  a national marketing club called DECA attracting many
students with talent and interest in  __2__. So I did.    
     The first  __3__  was to raise money for the marketing competition later in the year by selling
candles. Mrs. Tolman said the competition was due in a week and that 40 percent of the  __4__ would
go into my personal account.    
     At the beginning, I tried to sell some candles to my host mom. She said that if I could   __5__  
confidence and do a wonderful sales presentation, she would certainly buy some. I started my  __6__    
with a firm handshake. Then I introduced all the different kinds of candles and the special sales I could
offer and  __7__  her that our candles were the best choices for gifts and home decorations. Finally
she bought three candles.    
     Greatly  __8__  I decided to sell my candles around the neighborhood. On Saturday morning, with
great courage, I knocked at the door of my first potential  __9__.    
     "I'm a student at Skyline High School and we are __10__  money for DECA. I'm trying to sell..."  
      "Not today, sorry, "  the man interrupted me and __11__  the door.    
     Embarrassed, I walked away and said to myself the __12__ thing that might happen was being
refused like that again. I couldn't even count how many times I was __13__  with reasons like "Not
today" , "I don't have any __14__ money right now" or "I just bought some". __15__, I had to continue
with the day. __16__, a woman kindly bought nearly  $ 60 worth of candles. I couldn't even hide my 
__17__  and said "Thank you very much" to her with a bow.    
     After a  __18__  hard work, I turned in my $408 worth of sales of candles, which gave me $163 in
my own account. I was __19__  to find out I was the second highest seller in all classes.    
     It was the first time that I had worked as a sales person. This experience let me know that __20__ 
difficulties was only wasting time and a barrier in my way to success.

( )1. A. hold          
( )2. A. business      
( )3. A. chance        
( )4. A. income        
( )5. A. express      
( )6. A. presentation  
( )7. A. told          
( )8. A. puzzled      
( )9. A. buyer        
( )10. A. lending      
( )11. A. opened      
( )12. A. worst        
( )13. A. allowed      
( )14. A. more        
( )15. A. However      
( )16. A. So          
( )17. A. anger        
( )18. A. week's      
( )19. A. puzzled      
( )20.A. overcoming  		B. join          
B. English        
B. way            
B. candles        
B. show          
B. business      
B. convinced      
B. surprised      
B. seller        
B. raising        
B. knocked        
B. uneasy        
B. permitted      
B. extra          
B. So            
B. Secondly      
B. embarrassment  
B. hour's        
B. surprised      
B. dealing with   		C. build        
C. math        
C. challenge  
C. business    
C. make        
C. club        
C. explained    
C. shocked      
C. business man
C. returning    
C. burst into  
C. best        
C. refused      
C. little      
C. Therefore    
C. Firstly      
C. happiness    
C. year's      
C. calm        
C. accepting    		D. set          
D. sports        
D. choice        
D. expense      
D. expect        
D. interest      
D. requested    
D. encouraged    
D. shop keeper  
D. borrowing    
D. shut          
D. unhappiest    
D. demanded      
D. left          
D. For          
D. Finally      
D. sad          
D. month's      
D. lucky        
D. worrying about
查看答案