H１－B REF,Please help

My friend got H1-B REF letter from USCIS.USCIS want her to provide evidence of leaving USA after her TN expiration
她的情况是这样：
（１）２００７年１１月得到EAD(作为副申请人)。
（２）２００８年３月30日TN VISA 到期。
（３）２００８年４月１日递交H１－B申请

Questions:
(1)Did she have to leave USA after her TN expiration.
(2)How to write a letter to reply this REF letter.
(3)Is there any similar letter you can provide me?
(4)Could you provide some links about USCIS policy?

Thanks in advance

所有跟帖： 

• Xiaobaitu,Pijing and other experts ,Please give me help -grace_ugly- ♀ (0 bytes) () 06/13/2008 postreply 06:29:31

• 回复：H１－B REF,Please help -pjiang- ♀ (396 bytes) () 06/13/2008 postreply 06:56:32