Supporting document requirements for 4 family L visa applications.

My family and I will travel to China for tourism, so we will need L type entry permits.

If I submit four separate applications that are correctly filled out with all required information and photos, what are the requirements for supporting documents?

Do I need to make a copy of each set of supporting documents for each application, or can I submit one set of the following:
4 Proof of legal stay or resdence status
5. Documents showing the itinerary including round trip air ticket booking record and proof of hotel reservation
6. Certification letter from the working unit of the applicant
7. original copy of recent 6-month bank statement of the applicant.
8. Letter of why we are visiting PRC (again)

Best Regards;
Dave