follow牛津字典。

As follows (not as follow ) is the established form of the idiom,no matter whether the noun that precedes it is singular or plural:

As follows （不是 as follow ）是慣用語的構成形式,而不管前面的名詞是單數還是復數形式：

The regulations are as follows.

規則如下所述.

as follows只是壹種固定搭配,所以可以不符合語法.像這類固定搭配都是約定俗稱的,根本沒辦法從語法角度去分析,比如還有壹句“long time no see”是“好久不見”的意思,這也是壹種固定句式,不需要用語法去分析.

總之,as follows就是壹種固定說法,本身的詞性不需要具體分析.具體在句子當中做的成分應該理解成表語,因為“主語+be動詞+表語”是壹種基本句子結構.