it 完全可以代替动词或动词短语。如：

Most children who stammer grow out of it. 大多数口吃的儿童长大以后就好了。

He domineered, and the rest of us hated it. 他行事专横，我们大家都讨厌他这种作风。

Children who stay away from school do it for different reasons. 孩子逃学有各种原因。

Driving on the left is strange at first but you get used to it. 沿着路的左侧驾驶刚开始时有些别扭，可是习惯了就好了。

He was disappointed at not getting the job, but he’ll get over it. 他因没有得到那份工作而大失所望，不过他能想得开。

He will comb his hair at the table, even though he knows I don’t like it. 他偏偏要在饭桌哪儿梳头，还明明知道我腻味这事儿。