Innovations are occurring at a bewildering rate: as many now arrive in a year as once arrived in a millennium.

选自《Old Father Time Becomes a Terror》—Richard Tomkins

译文：新技术纷至沓来，令人目不暇接：一年涌现的技术创新相当于以前一千年。

请问老师这句话中的粗体字部分的as.. .as… 结构是什么意思？

这里的as...as 表示表示比较，多达...与...一样多意思"as many as 结构

第1个as为副词，修饰 as many,第2个as为连词，并从句充当成分。用以补充说明，技术创新速度很快，种类很多。

as many now arrive in a year as once arrived in a millennium

=as many innovations in a year as once arrived in a millennium.

(第2个as作为关系词在比较状语从句作主语成分）

参考译文：在一年中发明的数量与过去一千年发明的数量一样多。