_青岛成考网

51__________？

Of all ____ reasons for my decision to become a university professor, my father's advice was ____ most important on.

• A、the；a
  

• B、不填；a
  

• C、不填；the
  

• D、the；the

 We won’t keep winning games____we keep playing well.

• A、because
  

• B、unless
  

• C、when
  

• D、while