Please Help me on 485 questions.

Hi,
I have some questions regarding 485 material preparation.
1. Copy of birth certificate. I think people don't have birth certificate in China. I only have notary birth certification. Is the
copy of notary birth certification ok or I need to provide the original notary copy?
2. copy of tax return? Do I need to get the copy from IRS or just the copy I saved when I file my federal and state tax return.

Thank you very much in advance!

Zane