回复：对不起，还没完，一个技术性问题

when i submitted the application, i checked USCIS.gov. they do not mention any special address. you'd better make a double check.

you can us clips to attach each applicant's document together. do not mess them up. check should in the front. about photos, you can use three letter envelops. do not forget to write A# on the back of the photos.