同位语从句只用that作为开头（I have no idea除外） 为何

同位语从句只用that作为开头（I have no idea除外） 为何 I have no idea 后能否用that引导同位语从句 若能 请举个例子 i have no idea后到底接的是同位语从句还是宾语从句 I have no idea where he comes from是同位语从句? I have no idea what has happened to him为什么是同位语从句 为啥I have no idea when he will be back是同位语从句 I have no idea how soon they are coming .请问这句话中的从句时同位语从句还是定语 which 可以引导同位语从句吗?I have no idea which one I should choose?是什 I have no idea +从句 这个从句在句子中时宾语从句还是同位语从句还是 宾语补足语从句 I have no idea what size shoes she wears.后面的同位语从句,为什么主语在后面呢. "I have no idea where he comes from."是同位语从句吗?如果是,为什么连接副词wher HOW 能否引导同位语从句 例：You have no idea how depressed you have made