I am a H1b holder changed from J1. no H1b stamp on my passport. current h1b is volid till next March. I-140 approved, I-485 pending. have advanced parole already. my question is if i shall apply for employment authorization card (EAC) provided I am going back to china for 1 month and want to keep current job after coming back.If i don't have EAC, when i come back, will i still be legal to work with my h1b visa? please answer. many thanks.