返大陸可以用passport嗎？

Possible but they will ask you a lot of quesstions. Some 15 years ago, my university organized a trip to China and one of my classmates had his "Return Card" expired. The result was, all of us got through the immigration checks within 5 minutes and he took 90 minutes!

你係外國人咪可以law
中港奧人要用回鄉卡ga

可以，我試過。