就病例对照研究而言，下述哪项是错误的（） A.属于描述性研究 B.设立比较组 C.研

     What should we do to keep healthy? One important rule is to exercise    1   . The Fang family try to exercise
every day. Mr Fang    2    exercise in the morning because he must get to work at exactly seven o'clock. But he
runs every evening. He walks a lot,    3   . He walks to school every day, and after school he    4    different
sports with his friends. Mr Fang goes to a yoga (瑜加功) class    5   .
     But it wasn't    6    this way. Last year Mr and Mrs Fang used to (过去常常)    7    everywhere in their car,
even to the drugstore (药店) two blocks (街区) away. They thought they had to use the car all the time. They
wouldn't walk. 
    The Fangs all    8    better now. They believe they shouldn't be lazy. We    9    exercise every day, but we
should try our   10   to exercise as often as possible.

B. sometimes     
B. can not       
B. also          
B. plays         
B. for two weeks 
B. even          
B. drive         
B. make          
B. don't         
B. good          

C. late             
C. would not        
C. too              
C. loves            
C. after two weeks  
C. sometimes        
C. fly              
C. feel             
C. won't have       
C. well