I don't know when I can post the letter.改为同义句I don't know ___ ___ ___the letter.请问这是什么句型?为什么这么填?

I don't know when ( ) famous I don't know when leave 还是I don't know when to leaf I don't know when I have been loving I don't know. “i don't know you know i don't know 改错 I don’t know when will they come I don’t know when we shall start the work. 英语翻译I don't know when( )for Shanghai.(leave) when it left scars can heal~i don't know~ But I don't know when he---------(go to bed) I don’t know when he (arrive). When he (arrive) here, I will call you. I don't know when he ____,I must talk to him when he____.(come) sorry,I don't know. i don`t know much I don't really know. 英语；I don't know I don't know miss I don't know him.