— do you do in your free time?— Some outdoor activities.A. WhichB. WhatC. WhenD. Where

问题补充：

— do you do in your free time?

— Some outdoor activities.

A. Which

B. What

C. When

D. Where

答案：

A. Which

(答案→)B. What

C. When

D. Where

解析：Which哪一个；What什么；When什么时候；Where在哪儿。根据下文，一些户外活动。可知上文问的是，在你的空闲时间，你做什么？故选B。