52. (    )

48. It can be inferred from the passage that (   ). 

• A、when one is in a bad mood, he or she may not work very well
  
  

• B、the best way to overcome a bad mood is to talk to oneself
  
  

• C、some drugs are more effective than physical exercises
  
  

• D、taking drugs is at the risk of being poisonous
  
  

13. It was buying game cards that cost Jim most of the money that he (   ) on learning. (   ) 

• A、might have spent
  
  

• B、must have spent
  
  

• C、should have spent
  
  

• D、 would have spent