43. The passage is mainly about (   ). 

• A、a group of cold-water-swimming lovers
  
  

• B、the Polar Bears' life in New York
  
  

• C、doctors' ideas about cold-water swimming
  
  

• D、the requirements of the Polar Bear Club
  
  

41. According to the passage, some doctors believe it is true that (   ). 

• A、you are healthy if cold-water swimming turns your skin color blue
  
  

• B、cold-water swimming causes more heart attacks in summer than in winter
  
  

• C、cold-water swimming can make the body temperature dangerously high
  
  

• D、Polar Bears are bears swimming in freezing water
  
  

55. (   )