Oh man congratulations !I feel sorry for you for not knowing the actual scenario here in the USA. In some school, professor prefers Bangladeshi graduate students (GRA) (especially from BUET) more than any. I can give an example of my department. There are three Bangladeshi students doing their Ph.D. here in the civil engineering department. Guess what, how many Indians, None! In electrical department only one Indian GRA as compared to five Bangladeshi GRA. Even my professor rejected five IIT students to hire me. Get some knowledge man.