—can we find your brother at weekends?— On the football field。A. WhenB. WhichC. Why D. Whe

问题补充：

—can we find your brother at weekends?

— On the football field。

A. When

B. Which

C. Why

D. Where

答案：

A. When

B. Which

C. Why

(答案→)D. Where

解析：When什么时候；Which哪一个；Why为什么；Where在哪儿。根据下文，在足球场上。可知上文提问的是地点，故选D。