I haven't seen you for a long time.(同义句) I haven't seen you ____ a long time ____

I haven't seen you for a long time.(同义句) I haven't seen you ____ a long time ____

I haven't seen you for a long time.(同义句)
I haven't seen you ( since ) a long time( ago).
加油!不明白再问!

I have't seen you since a long time before.