there is no doubt+什么 ...一定是that?
问题描述：
there is no doubt+什么 ...一定是that?
答
应该是，定语从句
答
固定搭配no doubt that
答
doubt在此处是名词； that引导同位语从句
答
there is no doubt that ....
的确该句型要求后面跟that引起的从句。