我家成員屬加拿大公民， 持H1B 和H4簽證居住美國 (一孩子在加拿大上大學)，移民申請排期臨近，現準備遞交I-485。請問在加拿大上學的孩子( 持H4簽證) 如何申請移民身份調整?
可能有以下選擇: 1) 所有家庭成員的I-485同時遞交。
在外上學的孩子是否必須在遞交申請時返回美國?
-Not need. All your plans here are doable.
2) 主要成員在美國遞交I-485，在外上學的孩子同時在加拿大申請移民身份調整。
-This procedure is called immigration visa application outside US (in Canada in your case) using consulate processing. It is a good choice if your child will stay in Canada for a longer time. You just need to file I-824 for your child together with your I-485 filing, or file I-824 any time later after you file I-485.
3) 主要成員在美國先遞交I-485，在外上學的孩子在暑假返回美國後再遞交I-485。
請分析各種選擇的利弊。哪種選擇比較好?
-If your child will stay in Canada for a short period of time, choose 1) or 3), otherwise choose 2).
-Yes unless your I-485 is approved.
是否需要申請 Advance Parole Document 才能自由往返美國
-If he/she choose 1) or 3), he/she had better have AP in case your I-485 is approved before he/she returns to US
