is important for us to learn English well.A. WhatB. ThatC. ItD. Which

问题补充：

is important for us to learn English well.

A. What

B. That

C. It

D. Which

答案：

A. What

B. That

(答案→)C. It

D. Which

解析：考查it作形式主语。句子真正的主语是 to learn English well, 所以开头用it来作形式主语。句意：对我们来说学好英语很重要。所以答案选C。