The subject of these lectures ____by the lecture committee.这个题

问题描述:

The subject of these lectures ____by the lecture committee.这个题
我就想知道为什么B要不得 lectures是复数 has是用于单数的吧?
A) is announced B) have been announced C) are announced D) has been announced
难道has 的主语是the lecture committee?是的话 我太2了

因为subject是 单数的主语
of these lectures 是subject的定语