Question

【题目】_____ is even important _____ as the earth cooled down, water began to appear on its surface.

A. That, which B. What, that

C. What, what D. It, that

Answer 1

【答案】D

【解析】句意：甚至更加重要的是随着地球变冷了，水开始出现在它的表面。这句话使用it做形式主语，that引导的是真正的主语从句。所以选D。