－Where are the boys of Class Five?－I saw them basketball on the playground.A. played B .pl

问题补充：

－Where are the boys of Class Five?

－I saw them basketball on the playground.

A. played B .playing C. to play

答案：

解析：句意：五班的男孩去哪里了？我看到他们在操场打篮球。See sb. doing sth.看到某人正在做某事，动词用ing形式，故选B。