is ,was ,will be ,were的意思
is、was、will、will be的区别
填写适当的动词be(am, is, are, was, were)
am,is,are,be,been,was,were的区别
be able to的be可以换成is/was/am/were/are对吧
选择恰当词 is are would will was were where
who will be sent abroad__not known yet a.is b.are c.was 意思
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be 的正确形式填空并翻译( am is are was were)
用正确的be动词(am ,is ,are ,was,were)填空
什么情况下be是不用变成am is are was were 的
be.am.is.are.were.was.been.being.分别是什么时候用的