is necessary for us to tell him about the result.A. ThatB. ThisC. ItD. What

问题补充：

is necessary for us to tell him about the result.

A. That

B. This

C. It

D. What

答案：

A. That

B. This

(答案→)C. It

D. What

解析：考查it用法。本题的It是形式主语，真正的主语是后面的不定式to tell him about the result.句意：对我们来说，告诉他结果是必要的。故C正确。