be used 的用法be used to/as/by/for 区别,

used to + 动原,“过去常常”,
He used to drank.
be used to 译为“被用来…”,后接动原.
It is used to cut things.
be used to 译为“习惯于…”,后接动词ing或名词/代词.
如：
He’s used to working late.
We are all used to following others.
be used for + 目的（名词或动词ing）
如：English is used for business./Knives are used for cutting things.
In most cases,this module should only be used for debugging purposes.
在大多数情况下,这个模块只是用于调试目的.
However,it will need many more studies before the technique used in this
study can be used for diagnosis.
不过,在这项研究采用的技术能够被用于临床诊断之前,还需要进行更多的研究.
Theoretically,they could still be used for chewing,but in one third of
people,they can come in sideways,impacted,or can cause pain and infection.
理论上来说,它们现在仍然可以用于咀嚼,但是大约三分之一的人的智齿从侧面萌出,就可能会导致疼痛和感染.