替朋友求問8老師：
朋友申請父母綠卡已經批下來，visa要求6月份入境，現在有實際問題：
1, 第一次落地簽，在等正式綠卡期間的幾個月，返回加拿大等綠卡是否合法（加拿大國籍）？
-Yes. After they enter US using the immigrant visa, they become green card holders immediately. The IO will stamp/endorsed the visa at the port of entry which is qual to the temporary green card valid for one year. So, they can use this endorsed visa to travel out of US any time before they receive the plastic green card. But they had better not stay outside US for more than 6 months continuously.
2，如果合法，是不是從入境開始不超過180天？還是登完陸返回加拿大時開始算？
3，朋友有一個未成年的妹妹，如果父母為妹妹在美國申請綠卡，父母是否必須在美國有工作和至少有多少收入？-Not have to. But your friend needs to be the joint sponsor to provide the financial support if the parents have no income.
銀行存款是否可以作為收入？
首先謝謝8老師能回答，也謝謝有經驗的網友不吝賜教。
所有人豬年幸福，恭喜發財。
