A series of debates tetween the lectures was scheduled for the next week

问题描述:

A series of debates tetween the lectures was scheduled for the next week
A series of debates tetween the lectures ( )scheduled for the next week.
a was b were c have been d are
为什么选a?next week 是将来时啊,was 是过去时啊.还有lectures 不是可数名词吗?
但为什么是单数呢,lectures是复数啊

schedul的意思是计划 下周是将来的时间但是它表示的只是为下周做的一个计划 而在说这句话的时候 计划已经做出了 所以这里用过去式但为什么是单数呢,lectures是复数啊这里它的主语是A series of debates一系列的讨论 这是个固定用法后面谓语用单数