Using advanced parole?

My visa expired long time ago, and I am in H1b status. I have gotten Advanced Parole recently. I am planning to visit China by using AD.

Can some one tell me: 1) Is there any thing I should be careful about using AD? 2) Should I show the AP to the officer when I leave US border (I know I need to show it when I return to US)?

Thank you in advance!