52. (    )

20. —I usually go to school on foot. 

—Why don't you (   ) by bus for a change?

• A、try to go
  
  

• B、trying to go
  
  

• C、to try to go
  
  

• D、try going
  
  

43. What is the author's attitude towards the"law of nature"?

• A、Against.
  
  

• B、Supportive. 
  
  

• C、Skeptical. 
  
  

• D、Very much interested in.