50. The subject of a dream can change if (   ) . 

• A、the person is ready to wake up
  
  

• B、the sleeper is very relaxed
  
  

• C、the dreamer is overtired
  
  

• D、the person hears a noise
  
  

37. Which of the following statements is NOT true?

• A、People should take their naps secretly. 
  
  

• B、Cats have the same moods as people.
  
  

• C、Some famous people take cat naps.
  
  

• D、Some people have full energy after they lake cat naps.
  
  

53 .(    )