USE的几个用法？

be used to do （被动）某物被用来做某事
be used to doing 习惯做某事
used to do 过去常常做某事

be/get used to sth /doing sth

1. 习惯于
She is used to hard work./doing hard work
她习惯于艰苦工作。

used to do sth
ph.
1. 过去一向,过去时常;过去曾(而现在不再)做
He used to be a doctor

否定句 用 usen't to do / didn't use to to
疑问句亦是

be used to do 被用来做
used to do过去常常(既然是过去肯定要用过去式了)
get/be used to doing习惯于