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 是原来公司的律师,你也许会想要停用其服务。". The link to "停用其服务" 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.