39. If the information given in this passage is correct, when we look at a star at night (   ). 

• A、we will notice that it is not moving
  
  

• B、we cannot tell whether or not it still exists
  
  

• C、it is four years that the light we can see will reach us
  
  

• D、it will be brighter than the moon
  
  

49. "Feel out of sorts", as it is used in the second paragraph, could best be replaced by (   ).

• A、put things in order
  
  

• B、are in a bad mood
  
  

• C、search for tranquilizers
  
  

• D、want a mood-raiser
  
  

55. (   )