请问一句英语 虚拟的用法The entire building may have been destroyed by the fire ____ the fire department not responded so quickly.(A) if(B) had答案是B,为什么不选A,而选B呢?谢谢!

请问英语虚拟语气的用法 英语虚拟语气的用法? 请问一下英语中的各种虚拟用法 请问一句英语 虚拟的用法The entire building may have been destroyed by the fire ____ the fire department not responded so quickly.(A) if(B) had答案是B,为什么不选A,而选B呢?谢谢! 英语虚拟语气的用法求解 英语中虚拟语气的用法 请问 虚拟的市场 中的虚拟英语用哪个词? 关于英语中的虚拟语气,求解答!急!Q1: 句一：It looks as if it is going to rain. 句二：The apple tastes as if it is sour. 这两句是虚拟语气吗?如果不是,请问为什么不用虚拟语气；如果是,请问为什 虚拟语气的用法 虚拟语气的用法 虚拟氏的用法 虚拟语气的用法 虚拟条件句的用法具体说一下 虚拟语气中“only”位于句首的用法 除了if于wish引领的虚拟语气句外虚拟语气的具体用法 In the past men generally would rather that their wives work in the home.是虚拟语气句吗?、would rather 虚拟语气到底如何使用 此句中是虚拟语气的用法吗？ 请问虚拟语气中might的用法?The orders might have been withdrawn earlier,except for a number of events. 关于虚拟语气but for含蓄条件句的用法But for the opening policy,the situation in China _________what it is today.A would never be B will never have been C would never have been D will never be 请问：是否为错综条件句的虚拟语