_云南成考网

54. (    ) 

31. (      )

• A、common
  
  

• B、usual
  
  

• C、ordinary
  
  

• D、strange
  
  

40. The main idea of this passage is (   ).

• A、warfare is a "law of nature"
  
  

• B、warfare is not a "law of nature"
  
  

• C、warfare does not control human population
  
  

• D、none of the lowlier animals, except ants, practice warfare upon their own species