问题 选择题

用显微镜观察叶下表皮临时装片时,发现一气孔位于视野的右下方。要想使该气孔移至视野中央,装片应移向

A.左上方

B.左下方

C.右上方

D.右下方

答案

答案:D

本题考查的是显微镜的使用。在显微镜下观察到的是倒像,即上下颠倒,左右也颠倒。所以物象位于视野的右下方,实际是在左上方,应向右下方移动装片才能使要观察的物象移至视野的正中央。

完形填空
Jerry在欣赏一篇美文,可是中间缺了一些词,请你动动脑筋从所给的四个选项中选出恰当的词,使它成为一篇完整的短文。
      A rich father wanted to show his son how poor people can be. One day, he took his young son   1  
a trip to the country. They   2   a day and night in the farm of a very  3  family. When they got back from
their trip the father asked his son, "how was the   4  ?"
     "Very good, Dad!"
     "Did you see how poor people can be?" the father asked.
     "Yeah!"
     "And what did you   5   ?"
     The son answered, "I saw that we have a dog at home, but they have four. We have a pool that
reaches to the middle of the garden. They have a small river that has no   6  . We have expensive lamps
in the garden, but they have the  7  . Our…"
     When the little boy was finishing, his father was    8   .
     His son added, "Thanks, dad, for showing me    9     poor we are!"
     Isn't it true that it all depends on the way you look at things? If you have love, friends, family, health,
good humor and a positive attitude (积极的态度) toward life, you've got  10  !
( )1. A. on        
( )2. A. took      
( )3. A. rich      
( )4. A. trip      
( )5. A. say      
( )6. A. top      
( )7. A. suns      
( )8. A. wordless  
( )9. A. what      
( )10.A. nothing    
B. in      
B. paid    
B. poor    
B. idea    
B. learn    
B. bottom  
B. stars      
B. happy    
B. how      
B. something  
C. at      
C. spent    
C. good    
C. way      
C. remember  
C. end        
C. tents      
C. excited    
C. why        
C. anything  
D. to          
D. cost        
D. happy      
D. life        
D. write      
D. cover      
D. cages      
D. pleased    
D. when        
D. everything  
多项选择题