【回答】
It seems that it will really rain,won't it?
说明：这个句子虽然是It seems that句式,但核心意思指will rain“下雨”,所以,话题放在从句将来时：will...,won't it?
就像I think she is your friend,isn't she?一样,不能说don't
（刘老师
补充一下：再举个例子,如果说 It seems that they have finished their new house,____?你填doesn't it有意义吗?答案是：haven't they