How long is it valid?
它的有效期是多长时间？

I lost my Visa.
我的签证丢了。

I'd like to extend my Visa.
我要延长签证。

Can you tell me how to go through the customs?
你能告诉我怎么过海关吗？

I have nothing to declare.
我没有要申报的东西。

What articles are duty free?
哪些物品是免税的？

Can I bring this into this country?
我可以把这个东西带进这个国家吗？

How much can I take with me?
我可以随身带多少钱？