问题 填空题

在深度为4的满二叉树中,叶子结点的个数为 【1】

答案

参考答案:H

解析: 二叉树有一个性质,即在二叉树的第k层上,最多有2k-1(k≥1)个结点。而对于满二叉树来说,每一层上的结点数都达到最大值,即在满二叉树的第k层上有2k-1个结点。因此,在深度为4的满二叉树中,所有叶子结点在第4层上,即其结点数为
2k-1=2k-1=8

完形填空
完形填空。
     Perhaps you ride a bicycle to school. Riding a bicycle can be great fun. Do you know how to ride
a bicycle  1 ?
    Careful boys and girls learn to ride their bicycle well  2  they go out on the road. How can you
tell  3  you are a good rider?
     If you can ride a bicycle in a straight line, you can ride well. If you can't ,you should practise riding 
 4  a safe place. To be safe on a bicycle, you  5  to use both hands and both feet.  6  your
feet on the pedals and your hands on the handle bars at all times.
    Do you have a basket on your bicycle? If so, put your books and packages in it. Then you can
 7  both hands on the handle bars.
     You know that your bicycle is built for one person. It is not safe to carry anyone  8 you.   9  is this
so? Keep  10  safe by safety rules when you ride on a bicycle. Watch where you are going at all times.
( )1. A. safe      
( )2. A. as soon as
( )3. A. that   
( )4. A. in      
( )5. A. must      
( )6. A. Keep      
( )7. A. keep      
( )8. A. to       
( )9. A. Where    
( )10. A. it     
B. safety
B. before
B. how  
B. on    
B. need  
B. Make  
B. make  
B. for    
B. Why    
B. yours  
C. safely  
C. after  
C. what    
C. at      
C. may    
C. Let    
C. let    
C. with    
C. What    
C. you    
D. save    
D. until    
D. whether  
D. to      
D. can      
D. Get      
D. get      
D. by                                 
D. How      
D. yourself
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