I want to know___his homework yesterday evening.A:if he finished B:whether he had finished

问题描述:

I want to know___his homework yesterday evening.A:if he finished B:whether he had finished
为什么

B 过去的完成时呀.
这里不是虚拟语气,所以不要跟虚拟语气的完成时和过去式弄混了.