Question

25. In my opinion, life in the twenty-first century is much easier than ________.

25. In my opinion, life in the twenty-first century is much easier than ________.

A. that used to be B. it is used to C. it was used to D. it used to be

为什么不选A，that不也可指代么？请解释，谢谢

Answer 1

我觉得，生活在二十一世纪，是容易得多，比
a用可
b它是用来
c它被用来

Answer 2

惯用法,it用作指代比较多, that 则多用作连接词