问题补充:
I didn see your sister at the party. If she , she would have met my brother.
A. has come
B. had come
C. did come
D. came
答案:
A. has come
(答案→)B. had come
C. did come
D. came
解析:本题考查的是if条件句中的虚拟语气。句意:我在会议上没看到你姐姐,故你姐姐没来。因此如果“她来了”与事实相反,前面一句交代了虚拟语气的时态是一般过去时的虚拟,所以if从句中用had+过去分词。