16. It takes _____ hour to reach the top of the mountain.

• A、a
  
  

• B、an
  
  

• C、不填
  
  

• D、the
  
  

53.

43. How did Sally feel before she got on the bus to school alone?

• A、Proud and worried.
  
  

• B、Lonely and frightened.
  
  

• C、Delighted and surprised.
  
  

• D、Excited and nervous.