所得级距的英文：
income bracket

income是什么意思：
n. 收入；收益；所得

IQC Incoming quality control
来料检验

Incoming fire has the right of way.
飞来的子弹有优先通行权。（挡它的道你就要倒大楣！）

He has a comfortable income.
他有充裕的收入。

The data on Argentine incomes are sparse.
有关阿根廷国民收入的资料不多。

His income is incomparable with mine.
他的收入不能与我的相比。

bracket是什么意思：
n. 括弧，括号；托架；类别，等级；阶层
v. 括在一起；把…归入同一类；把…分类；为…装托架

Delete the items in the bracket as appropriate.
删除括号中不适用的称谓。

They bracketed discussion off for a moment.
他们对问题暂停讨论。

The children were bracketed into groups.
孩子们被分成几类。

Don' t bracket them ( together ).
不要把他们相提并论。

I think you should bracket this word.
我认为你应该给这个字加上括号。