I am doing research in USA,and hold H-1B visa, I also have MD in China, so i want to take the exam for the license of a doctor.But if I apply for green card, it was said doing research is much easier than a doctor.I assume that I can finish the exam in two years and begin my residency after that, maybe within two year after pass the exam, the problem is when I begin the residency, the green card may not available at that time(3 or 4 years later), does anyone have similar experience, can you give me some suggestion? Thanks a lot.