的比赛I think Ann must () on duty today.A.be B.is C.are D.am

来源:学生作业帮助网 编辑:作业帮 时间:2024/04/30 20:35:02

的比赛I think Ann must () on duty today.A.be B.is C.are D.am
的比赛
I think Ann must () on duty today.
A.be B.is C.are D.am

的比赛I think Ann must () on duty today.A.be B.is C.are D.am
A
must是情态动词
情态动词后接动词原形
还可以这样:
先排除C、D(人称不符)
再.