什么是external tax和internal tax？将external tax翻译为进口税或者外税我不是很理解。请求详解~~

FROM WIKI. ANSWERS.COM
external tax 产生于美国独立前、英殖民地时期，进口货物的附加税。（只为增加税收而征税，不向殖民地人民说明用途，最后导致独立战争爆发）
Tax levied on goods coming into the colonies, like sugar, molasses, foreign goods. Although the colonists had no say in how these taxes were spent, they generally considered Parliament had the right to levy the tax.

External tax. A duty for the purpose of raising revenue.
Since the early years of colonial America, the British had used duties to regulate trade. The Americans largely accepted such duties. In 1764 and 1765 the British Parliament imposed duties for the purpose of raising revenue, and then an internal tax in the form of an excise tax collected through the use of stamped paper.

The Americans objected that the internal tax was unconstitutional. The British constitution-and the natural rights of mankind- limited the right of taxation to the representatives of those taxed. Since the Americans were not represented in Parliament, they could not tax the Americans. Hence the cry of