Question

【题目】__________ has already been pointed out, grammar is not a set of dead rules.

A. It B. Which

C. As D. What

Answer 1

【答案】C

【解析】考查特殊定语从句。句意：有人指出，语法并不是一套死规则。As has already been pointed out相当于as is known to all.选C。