Thanks for the reply.TX center.

TX center.They cashed the check within 2 weeks(I used first class regular mail).Since the Human Resource said that I should renew now, I sent the application 5 months before my EAD expire date. Althought the USCIS website says that one should renew EAD no realier than 3-4 months bofore it expire.Good luck to everyboday!