— do you usually come to school?—By bike.A. HowB. WhatC. How oftenD. When

问题补充：

— do you usually come to school?

—By bike.

A. How

B. What

C. How often

D. When

答案：

(答案→)A. How

B. What

C. How often

D. When

解析：由答语by bike 可知是对交通方式的提问。提问交通方式应该用疑问词how。而B什么，用来提问物等，C多久一次，用来提问频率D何时，用于提问时间。