翻译：正如/就像报纸上被报道的那样,他很受年轻人欢迎.
解释：此题的as并非引导原因状语从句,而是引导非限制性定语从句.
1. as代指后面整个主句he is very popular among young adults所表示的内容,在该非限制性定语从句（被动句）中充当主语.
但是翻译时类似于比较状语从句,as翻译为“正如/就像”.
英语语法中,只有as/which可以代指整个主句,且只有as所引导的非限制性定语从句可以放在主句之前.
2. 再如：As we all know, the sun is larger than the earth.
其中,as = the sun is larger than the earth,在定语从句中充当know的宾语.
即：as we all know
= we all know as
= we all know (that) the sun is larger than the earth