If it ______for the heavy rain,we could have left for Paris yesterday.

题目

If it ______for the heavy rain,we could have left for Paris yesterday.
A.were not B.had not been
为什么A不行呢?
还有选项C was not

答案

if引导条件状语从句,主句都是将来完成时从句肯定要用完成时．