As has been announced,we shall have our exams next week.

问题描述:

As has been announced,we shall have our exams next week.

正如被宣布的那样我们下周考试。所以As 在这里是正如的意思。

As(正如) has been announced,we shall have our exams next week.(插入语结构)
==It has been announced that we shall have our exams next week.(主语从句)
===That we shall have our exams next week has been announced (by the school).(主语从句)
===we shall have our exams next week,which has been announced (by the school).(定语从句)
=== What has been announced (by the school) is that we shall have our exams next week.(表语从句)