题目内容：

I won't go to her party unless my best friend jack____.
A.will invite B.will be invited C.is invited D.invetes
为什么选C?

优质解答

因为unless引导条件状语从句,从句里要用一般现在时代替将来时,所以这里选C.
unless= if not.
翻译：除非我最好朋友杰克被邀请,不然我不去她的聚会.