Thanks, Laoshi. it's very helpf. one more qestion - when I went through your blog, i saw the following
"如果你的 I-485 是原來公司的律師,你也許會想要停用其服務。". The link to "停用其服務" at
http://blog.wenxuecity.com/blogview.php?date=200707&postID=22325#Fee
didn't give specifics how i can notify the USCIS to cancel my former co's lawyers' services. Please advise. Thanks again.