求解释句子里后面那个it is 的作用,能理解,

问题描述:

求解释句子里后面那个it is 的作用,能理解,
For those who don't smoke,it is much easier not to start smoking than it is to quit it.(是不是than后接quiting it 也可以?)

这道题是这样的:it is 有这么一条语法用法,在句子中用作形式主语,就像it is +adj (for sb) to do中it is 一样的,真正的主语是to do.不可以.因为:than在比较级中多用于平行结构,也就是说前面是    &nbs...