it was agreed that Miss Susan Wenworth be co-opted as Social Convener.请问这句话是虚拟语气吗?

问题描述:

it was agreed that Miss Susan Wenworth be co-opted as Social Convener.请问这句话是虚拟语气吗?
如果不是,请帮我仔细分析一下语法,

是的,从后面从句里面用了个be可以看出,按理说从句应该用动词说这个人成为了什么,但是从句用了原型,说明虚拟语气从句的should省略了