is very important for us students to learn English well.A. AsB. ThereC. WhatD. It

问题补充：

is very important for us students to learn English well.

A. As

B. There

C. What

D. It

答案：

A. As

B. There

C. What

(答案→)D. It

解析：it作形式主语，后面的不定式作真正的主语。考查句型It is+adj.+for sb.+to do sth.。