has already been pointed out is that grammar is not a set of dead rules.A. AsB. ItC. What

问题补充：

has already been pointed out is that grammar is not a set of dead rules.

A. As

B. It

C. What

D. Which

答案：

A. As

B. It

(答案→)C. What

D. Which

解析：句意：我们需要指出的是语法不是一系列的死的条文。此处what在主语从句中作主语，意为：……的。故选C。