回复：回复：回国问题请教

You have to apply AP and use AP to travel outside US if you want reserve you I485 application. Normal AP is valid for one year, you can apply admission on the port of entry with AP. You might subject cross-examination about your intention to stay in US.That is beauty of US immigration law that is subjectivity. That depend who examine you and your whole situation ( your resident, your intent, why you take the trip, how long is the trip,how nice the person is, how nice you are etc )
For the most safest method
before you leave us, apply AP/EAD, you go back china, and apply immigration visa in china using consular processing.When you want to go US, you can use AP or H1-B depending the time you want to come to US. Before one year, you can use AP/EAD. after one year, your I485 is abandon unless you go to US to apply other AP/EAD, you can only use h1-B. But you still have immigration visa pending. You can only continue use H1-B for past seven years.