separate and complete documents for a single case.

You need three copies for every required document. For example.
1. I485 for applicant 1, one complete set including everything. A personal check only for this 485 application can attach to the front page (cover letter). 2-hole punch assembly.
2. I 131 for applicant 1, one complete set including all required documents. A separate check with amount only for this case. 2-hole assembly.
3. I 765 for applicant 1, one complete set.a separate check. 2-hole assembly.

For every applicant, there are three separate and complete sets. You can put all three sets in a bigger envelop and print your name on this envelop.
If you have 3 people, you have three bigger envelops with their names on. Finally put all three envelops into the UPS or USPS box for delivery. mail with tracking number is a must so that you will know when USCIS receive your mail.

Sorry I can not type Chinese in my computer. Hope this is helpful for you. It is my experience. It works for me.

Good luck!