一、单项选择
（ ）1. He was the first one in the _______ history of the U.S to win that prize.
A. fifty-years B. fifty-year C. fifty years D. fifty year
（ ）2. His sister ________ a speech contest yesterday.
A. entered B. went in C. takes part in D. took part in
（ ）3. Liu Liang spends five hours _______ the piano every day.
A. playing B. plays C. to play D. play
