— did you start school?—I started school at five.A. HowB. WhyC. WhenD. Where

问题补充：

— did you start school?

—I started school at five.

A. How

B. Why

C. When

D. Where

答案：

A. How

B. Why

(答案→)C. When

D. Where

解析：How如何，怎样；Why为什么； When 什么时候；Where在哪儿。根据下文，我在五岁开始上学。可知上文问的是时间，故选C，你什么时候开始上学的？