We are going to have a barbecue _______ it r..

题目

We are going to have a barbecue _______ it r..

答案

选D unless=if...not...
补充一下为什么不能选择 C
except that 后面可以接句子,但是意思不太顺.除了当天下雨的时候,还可以说的过去,要用except when.
你自己体会一下吧.