all of us后用is还是are

到底是什么啊

肯定是are啦， all代表“三者或以上”

are

这三种结构的相同点: 意思相同,都表示"众所周知/我们大家都知道" 不同点:用法各不相同. it is known to us all中的it为形式宾语,因此这种结构后必须接一个主语从句来作真正的主语. 这个主语从句可以是that或wh-类连词引导的从句.即: it is known to us all+that/what/when/where/how从句. as is known to us all是由as引导的定语从句, as指代后面或前面的整个主句,因此as is known to us all结构可放句首,也可放句中或句末, 但一定要用逗号与主句隔开. what is known to us all是一个名词性从句,常用来作主语从句,用于这个结构中: what is known to us all is that.... 例如: it is known to us all that he will visit our school tomorrow . =as is known to us all , he will visit our school tomorrow . =what is known to us all is that he will visit our school tomorrow . as is known to us all, the earth goes round the sun! =it is known to us all that the earth goes round the sun! =what is known to us all is that the earth goes round the sun! it is known to us all when the meeting will be held . it is known to us all where the meeting will be held . it is known to us all why you didn't come to school yesterday.

all表示全部的概念，谓语动词应用复数形式用are下次简单all用are就行了