______the house will be built will be discussed at tomorrow's meeting.

问题描述:

______the house will be built will be discussed at tomorrow's meeting.
为什么不能用if?
A.If B.Where C.That D.What

B
这句话的意思是 将要把房子建在哪里这个话题将要在明天的会议上被讨论.
一开头一直到built 做整个句子的主语、
be discussed 是一个被动语态,指被讨论.