she would go and inform him if she --- his address.A know B

过去虚拟条件句时态：if +had+动词过去分词,所以选B
再问： if sb had done ... , ... would have done if sb did/ were ... , ... would do .... 这种形式才对啊
再答： 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