My children and I hold Canadian passport. And my children is in China now, and I have bought tickets for the end of August. But now we can file 485 after July 1, so, anyone can help me clearify whether I can pick them and back to US with H1B visa before Sept. 1 ( I will stay at China for about 2 weeks, and my H1B expire on 2009)? My 485 can be filed before the end of JULY. Also, if I file my children's 485 after they come back, will it slow my application. Thanks.