as known to us 还是as it is known to us?

1.as is known to us才是对的.
as引导的是一个非限制性定语从句,as代替整个主句,在定语从句中充当主语.
如：As is known to us,the earth goes around the sun.
2.“几月几日”的英语表达为：
“月份 + the + 序数词”,或“月份 + 序数词”再或“月份 + 基数词”
而且其中月份后面一般都有个逗号隔开.
日子用基数词表达也是可以的,但的确少见.
如：四月一日：April,the first / April,first / April,one