http://www.uscis.gov/files/article/OPT_4Apr08.pdf
变化不太大。
1. Limits of unemployment 还是没有提
2. 原来说申请费 $380，现在又变回 $340了
3. 原来说申请 extension 要 at least 90 days before OPT expires，现在变成
Students may apply for an OPT extension at any time prior to the expiration
date.
4. 但是，又说：If their post-completion OPT expires while the 17-month
extension application is pending, students who timely filed their STEM
extension applications with USCIS will receive an extension of employment
authorization after their curr
