A：You've traveled abroad a lot, Jim, so would you like to tell me something about clearing customs.
      吉姆，你经常出国旅游，能向我介绍一下关于通关的情况吗？

B：When you arrive in a country, you clear customs. A lot of countries have two channels: the green channel and the red channel. Some countries, like India, have three channels: the white channel, the green channel and the red channel.
      到达一个国家时要通关。许多国家的海关有两种通道：绿色通道和红色通道。还有些国家如印度有三种通道：白色通道、绿色通道和红色通道。

A：Then what are the differences between the green channel and red channel?
      那么绿色通道和红色通道之间有什么区别呢？

B：If you have more than the duty-free allowances or prohibited goods, you go through the red channel and declare them to a customs officer. If you otherwise have nothing to declare, you go straight through the green channel unless you are asked to stop by an officer. 如果你携带的东西超出免税的范围或属于禁带物品，你
      就得从红色通道通过并向海关官员申报物品。如果你没有需要申报的物品而海关官员又没有阻拦你，你就可以直接通过绿色通道了。

A：I see.I'm told that we'll have to state the purpose of going to a certain country, is it true?
      我明白了。我听说去一个国家时需要陈述旅行的目的，是吗？

aboard的解释

B：That's right. People go aboard for different purposes: some for pleasure, some on vacation, some on business, and some for other purposes.
      是的。人们出国都各有目的：有的为了消遣，有的出去度假，有的是因公出差，有的是为了其他目的。

A：I'm going to New Zealand for sightseeing. What should I say if they ask about my purpose?
      我要去新西兰观光，如果他们问我旅行的目的我该怎么说呢？

aboard

B：Just saying "sightseeing" is OK.
      说"观光"就行了。

1. 在（船、飞机等）上
    If you are aboard a ship or plane, you are on it or in it.

aboard的翻译

    e.g. She invited 750 people aboard the luxury yacht, the Savarona...
           她邀请了750人乘坐豪华游艇“萨瓦罗纳”号。
    e.g. They said goodbye to him as he got aboard the train at Union Station.
           当他在联合火车站登上火车之际，他们向他道别。