填写适当的动词be(am, is, are, was, were)

填写适当的动词be(am, is, are, was, were) are is were was am 分别是什么主语的be动词 用be动词（am,is are ,was,were）的正确形式填空 用正确的be动词（am ,is ,are ,was,were）填空 一般疑问句的构成?由be（am ,is,are,was,were ,） \情态动词（can is are were am was 分别是什么主语的be动词 英语练习题.填上适当的be动词或助动词,并写出相应的答句.am is are was were do does did1 am,is,are,be,been,was,were的区别 用be动词的适当形式(am,is,are)填空 关于be动词 am,is,are 的过去式 was 和were 的用法.我已经知道was 和were 是前者的过去式. be able to的be可以换成is/was/am/were/are对吧 is----------was.are---------were.am---------?