比较级 than的前后如何对等比较?

题目

比较级 than的前后如何对等比较?
It is more important to work at a job that you enjoy than it is to earn a lot of money.
than的后面为什么要加it is?
但可以直接用to earn吗?就是it is more important to work at a job that you enjoy than to earn a lot of money

答案

than 相当于 and ,要求其前后要对等than 前面是 It is more important to work at a job that you enjoy所以后半句也要用it is 做形式主语相当于To work at a job that you enjoy is more important than to earn a ...