i don't know what to say 同义句

问题描述:

i don't know what to say 同义句
i _______ _______ _______ what to say

I have no idea what to say.
have no idea 和 don't know 是一个意思,都是"不知道"的意思.
例如:I don't know who he is.
I have no idea who he is.
都是“我不知道他是谁”的意思.