A．单项选择，选出可以填入空白处的最佳选项。（共15小题，每小题1分，满分15分）
( )21.There is _______football in our classroom. Let's go to play _______football now.
A. a; a B. a; ／ C.／;a D. a; the
( )22.They have a PE lesson_______ Friday afternoon.
A．at B．in C．on D./
( )23.Alice and Tom like music.
A. to listen at B. listen to C. listening to D. listening
( )24．-_______ do you go walking'? _______ Three times a week.
A. How long B. How much C. How often D. How many
