18. This new model of car is so expensive that it is (   ) the reach of those with average incomes. 

• A、over
  
  

• B、within
  
  

• C、beyond
  
  

• D、below
  
  

51. (    )

38. We can know from the information given in the passage that the moon must be about (   ) away from us. 

• A、one million km
  
  

• B、350,000 km
  
  

• C、300,000 km
  
  

• D、400,000 km