过去虚拟条件句时态：if +had+动词过去分词,所以选Bifsb had done ... ,... would have done ifsbdid/ were ... , ...would do .... 这种形式才对啊说得好这是错综条件句结果主句和条件从句的谓语动作若不是同时发生时，虚拟语气的形式应作相应的调整。从句的动作与过去事实相反，而主句的动作与现在或现在正在发生的事实不符eg：If I had worked hard at school,I would be an engineer,too. 如果我在学校学习刻苦的话，我现在也会成为一个工程师了If they had informed us,we would not come here now. 如果他们通知过我们的话，我们现在就不会来这里了 相信你能明白了吧