－－－郵寄材料裏的efiling recipt是填完表格之後生成的Confirmation Receipt？還是幾天之後uscis 郵寄過來的official Receipt Notice (Form I-797) ？
-It is the Efiled verification receipt (print it out) and send all the support documents with this receipt to the address indicated in the Efiled verification receipt
－－－到底是郵寄i94原件還是copy？
-Photocopy is OK.
－－－郵寄可以用usps express嗎？還是普通平郵？
-If the address is mailbox, no Express Mail.
