First you have to know what is 旅行证 for. 旅行证 is for going back to China , not enter USA.They should have applied US passport for their kid(s) before leaving the country.
【在 m*********e 的大作中提到】 : First you have to know what is 旅行证 for. 旅行证 is for going back to China : , not enter USA.They should have applied US passport for their kid(s) before : leaving the country.