Before I started high school I used to spend a lot of time games with my friends.A. play

问题补充：

Before I started high school, I used to spend a lot of time games with my friends.

A. play

B. plays

C. playing

D. played

答案：

A. play

B. plays

(答案→)C. playing

D. played

解析：本题为固定词组用法：主语+spend 的适当形式+（in） doing sth，故选C