回複：回複：last question!

Is that true that once I use the EAD, I can not apply
or return back to the H1 any more (no matter I am in US or in China)?
-Not rue. You still can apply for an H1 visa outside U.S. (e.g. China) to enter US to get an H1 status, but it may affect your I-485. Of course, if your I-485 is denied first, and then you apply for the h1 visa in China later, that is not a problem and you can apply for the green card again.