I didn’t hear the doorbell because I ______ to music at that time.
A. listen B. will listen C. am listening D. was listening
I ______ Mr. Li many times already. I’m sure he isn’t at home.
A. call B. am calling C. have called D. will call
Sam ______ more progress if he works harder.
A. makes B. made C. is making D. will make
—What are the children doing in the park?
—They ______ kites.
A. fly B. flew C. are flying D. will fly
My parents often______ me some gifts on my birthday.
A. buy B. bought C. will buy D. have bought
（题文）Beijing is one of________cities in the world．
A. big
B. bigger
C. biggest
D. the biggest
