— is your sister?—She is eight years old.A. HowB. How oldC. WhatD. Where

问题补充：

— is your sister?

—She is eight years old.

A. How

B. How old

C. What

D. Where

答案：

A. How

(答案→)B. How old

C. What

D. Where

解析：考查疑问词。How怎样，How old 多大，What什么，Where在哪儿。根据答语内容She is eight years old.可知上文问的是年龄，故选B。