问题 选择题

将参加夏令营的500名学生编号为:001,002,…,500,采用系统抽样的方法抽取一个容量为50的样本,且随机抽得的号码为003,这500名学生分住在三个营区,从001到200在第一营区,从201到355在第二营区,从356到500在第三营区,三个营区被抽中的人数为(  )

A.20,15,15

B.20,16,14

C.12,14,16

D.21,15,14

答案

答案:B

根据系统抽样特点,被抽到号码l=10k+3,k∈N.第353号被抽到,因此第二营区应有16人,所以三个营区被抽中的人数为20,16,14.

完形填空
完形填空。
     How would you like to go to a school like this one in Oxford, England? There are no formal classes.
The students   1   from one group to another when they want to.  2  may find students who are fourteen,
fifteen or sixteen years old all in the same    3   . They work at their own speed.  4     tells them what they
should or shouldn't be doing.  The day I   5   , school began at nine. Some students were working    6   a
tape recorder and listening to their own voices. Others were watching a TV program   7   physics. A third
group was working in the library. I didn't see anybody just sitting doing    8   . Nobody was wasting time.   9  the students taking a break in the cafeteria were having a   10   on politics (政治).
( )1. A. move      
( )2. A. You      
( )3. A. grade    
( )4. A. Somebody  
( )5. A. visited  
( )6. A. on        
( )7. A. in        
( )8. A. something
( )9. A. However  
( )10. A. drink    
B. study      
B. A man      
B. school      
B. A teacher  
B. moved      
B. with        
B. according to
B. much        
B. Even        
B. show        
C. travel  
C. He      
C. class  
C. Nobody  
C. studied
C. for    
C. on      
C. anything
C. Also    
C. debate  
D. stay            
D. I              
D. group          
D. The group leader
D. stayed          
D. Through        
D. by              
D. nothing        
D. Only            
D. quarrel        
判断题