— do you usually go to school?— On foot. A. WhatB. WhenC. Why.D. How

问题补充：

— do you usually go to school?— On foot.

A. What

B. When

C. Why.

D. How

答案：

A. What

B. When

C. Why.

(答案→)D. How

解析：疑问词辨析. What什么;When什么时候; Why为什么; How怎样.根据答语是步行，表示方式，故选特殊疑问词为how，故选D