“what i said is true”这里的what能否换成that?为何?

I know what you said is true. I think what you said is true的同义句 O__,what you said is not true. -----------（实际上),what she said is not true What the doctor said is true. what mary said is ____(possible )true . “what i said is true”这里的what能否换成that?为何? I am sure what I said is true这句话对吗 I am sure that what he said is true.是什么从句 I am sure___you said is true.答案是what,为什么不是that i am sure()he said is true.为什么中间用what引导. What you said yesterday s___ me.Is that true? Let us s_________ what he said is true. what her said is true英语句子改错 is,what,true,he,said,partly.连词组句 what he said is ——- （probable） true What you said is true,every bit of it. 为什么I think that it is true是附属简单分句,而What you have said is true是复杂分句?