-did you start studying English ?---Five years ago.A. WhenB. How longC. How oftenD.

问题补充：

---- did you start studying English ? -----Five years ago.

A. When

B. How long

C. How often

D. What

答案：

(答案→)A. When

B. How long

C. How often

D. What

解析：四个选项分别表示什么时候、多久、多久一次和什么，根据答语五年前，可知选A。