留学生过海关时，以下是一些基本的英语表达，可以帮助你顺利通关：
基础问候
"Good morning/afternoon, officer."
出示文件
"May I have your passport, please？"
"Here is my customs declaration form."
说明目的
"I'm here for [purpose of visit]."
"I'm visiting for [specific reason, e.g., tourism, study]."
询问信息
"Could you explain how to fill this out？"
"Where can I collect my baggage？"
申报物品
"Do you have anything to declare？"
"I have nothing to declare."
询问停留时间
"How long will you be staying？"
礼貌用语
"Please."
"Thank you."
其他可能的问题
"Where are you coming from today？"
"What's your name？"
"And your birthday？"
记得保持礼貌和耐心，如果有任何疑问，可以请求海关官员的协助。祝你通关顺利!