“附加在后面”的英文怎么说

the certificate of public is attached to the back

The document is attached in the annex.
Annex就是夹在征文后面的文件。

不然的话就写：The document is enclosed.
文件付含在这里。

attach to the document

We attached several riders to the document.
我们在主文件上加了几条附文