be used as 和 be used by 区别

问题描述:

be used as 和 be used by 区别

be used as 是指被用来做……
比如It is used as a teaching centre.它被用来做教学中心.
be used by 是指被……(某人)用来做
比如It is used by the doctors as a teaching centre.它被医生们用来做教学中心.