---do your improve your English ?---I improve my English by English movies?A. What; watchi

问题补充：

---do your improve your English ?

---I improve my English by English movies?

A. What; watching

B. What; watch

C. How; watching

D. How; watch

答案：

A. What; watching

B. What; watch

(答案→)C. How; watching

D. How; watch

解析：What，什么；How，怎样；by doing sth.通过某种方式或手段。句意：你是怎样提高你的英语的？我通过看英文电影来提高我的英语。所以选C。